Music Theory for Producers: Turn a Chord Loop into Basslines and Arpeggios

Play A–C–E together, then keep A and C still while E rises to F. You have changed Am into F with one moving note. That small decision is music theory doing a producer’s job: making a loop’s parts connect.

Here you will build Am–F–Dm–Em, give it an arpeggio and a bassline, and move the whole sketch into B minor. You can enter the notes in a MIDI editor or play each part separately. Here middle C is C4, MIDI note 60; if your software labels octaves differently, use that pitch number as your reference. If intervals and note values are new, start with our music theory foundations.

1. Choose home before choosing more notes

Use A natural minor: A, B, C, D, E, F, G. A half step, or semitone, moves to the next piano key, counting black and white keys; a whole step is two half steps. Its octave pattern is whole–half–whole–whole–half–whole–whole. Number the notes from A: A is degree 1, C is 3 and E is 5. Scale Degree Names introduces this vocabulary; here G is the subtonic, a whole step below home, rather than a leading tone.

A natural minor begins on A and returns to A one octave higher. The engraved labels pair each pitch with its degree, so the upper tonic reads 8. Read the two half-step pairs B–C and E–F, then compare the final G–A whole step. The eight quarters fill two 4/4 bars in one key.

A collection supplies possible notes; it does not establish a key by itself. C major shares these seven names. Sustain a low A, play the collection above it, and finish on A–C–E. Then stop the drone and hear whether A still feels settled. Parallel vs Relative Minor separates shared notes from shared home notes.

The third above A is C, three half steps higher; A major would use C♯. Compare that change with Major & minor. For keyboard practice, the lower comparison on Scales in Every Key: A minor includes natural minor; the main two-octave exercise uses harmonic minor. We will keep G natural in this loop.

Try a short home-note test: play A3–B3–C4–E4, then D4–C4–B3–A3 in quarters. Stop after the last A and sing it without the keyboard. Next end the same experiment on B. Compare how unfinished that ending feels in the A context you established. This is a listening experiment, not proof that the final note or first chord identifies every passage’s key.

2. Build four chords you can name

Take alternate scale letters to make a root, third and fifth. Am is A–C–E; F is F–A–C; Dm is D–F–A; Em is E–G–B. Give each chord one complete 4/4 bar. The chords of a minor key places these choices among the seven natural-minor triads. Together our four chords use all seven scale notes.

Four bars, one chord per bar: Am–F–Dm–Em. Each whole-note stack lasts four quarter-note beats. The Roman numerals name each root’s A-minor degree and its major or minor quality. F is the only major chord in this selection; the other three have a minor third above the root. B appears in Em, completing the seven-note collection used across the loop.

Measured from A, their roots are degrees 1–6–4–5, so write i–VI–iv–v. Lowercase means minor; uppercase means major. The numerals describe roots and quality, not which note you put at the bottom of a clip. Chord symbols helps decode suffixes; our chord-building lesson explains the underlying thirds.

You could replace Em with E major, E–G♯–B. G♯ is a half step below A, giving a leading tone when it rises to home. That option changes the pitch collection. The three-minor comparison explains raised sevenths, but minor-key music also uses minor v; the Puget Sound chapter documents the wider chord vocabulary. Keep Em for the main exercise.

Only the third of the E chord changes: G becomes G♯ while E and B stay. G♯ is the leading tone a half step below A; G natural is a whole step below it. Compare either E chord with the following Am at the same tempo. This separate comparison introduces a harmonic option; it does not replace the Em in our four-bar natural-minor exercise. The separate two-note lines show the possible resolutions; the root-position chord stacks compare chord spellings.

Listen to Em–Am and E–Am at the same volume and speed. Name the changed note before describing the effect. Neither version is a requirement for a genre; choose the one your phrase needs. For other starting progressions, our progression guide offers a broader comparison.

Check a chord by measuring from its own root, not the key’s tonic. D–F is three semitones and F–A is four, so Dm is minor. F–A is four and A–C is three, so F is major. In the key, F is degree 6; inside the F chord, F is the root. Keeping those two numbering systems separate prevents a “sixth chord” label from replacing the plain F triad.

3. Connect the voices inside the clip

Start with root-position triads, then try A3–C4–E4, A3–C4–F4, A3–D4–F4 and G3–B3–E4. These are the selected voicings on Voice a Chord Loop in MIDI.

In the selected version, Am→F keeps A3 and C4 while E4 rises one semitone. F→Dm then moves only C4 to D4. Dm→Em moves every voice downward. Both versions retain the same chord identities and four-beat lengths; the comparison changes their register and inversion rather than their harmonic rhythm. The added labels show which root-position notes move up one octave to obtain the selected voicings.

A voicing is the arrangement of chord tones across registers and parts. An inversion specifies which chord member is lowest. In the F clip, A is lowest, making first inversion; Dm has A lowest, making second inversion. Triads & their inversions gives the basic shapes. None of these rearrangements changes F into Am: F–A–C remains the chord’s pitch set.

Root position puts the root lowest. To make our F voicing, move F3 in F3–A3–C4 up one octave to F4, leaving A3 and C4 in place. For Dm, move D3 and F3 up an octave while keeping A3. For Em, move only E3 up to E4. In your own loop, try octave moves that keep the new chord near the preceding one, then follow each voice and listen across the return to bar 1.

The roll represents the same selected pitches as the lower staff in the preceding comparison. In bar 2, the three rectangles occupy A3, C4 and F4, all beginning together and lasting four beats. The lowest rectangle is A3, yet the pitch set spells F major. Read rows by pitch and columns by time; the neutral background shading simply separates semitone rows.

Follow the bottom, middle and top voices separately. Am→F moves 0, 0 and +1 semitones. F→Dm moves 0, +2 and 0. Dm→Em moves −2, −3 and −1. Adding absolute distances gives 1, 2 and 6. Those totals describe these choices, not the smoothest possible arrangement. Play the top line E4–F4–F4–E4 alone, then restore the other voices.

A plus sign means upward motion and a minus sign means downward motion. Add absolute distances when measuring total travel: descending two, three and one semitones adds to six, not minus six. The return from Em into Am also matters; these voicings move two, one and zero semitones at that seam. The arithmetic measures the chosen voice assignments and does not rank every possible voicing.

Do not stop your voice-leading check at bar 4. Returning from G3–B3–E4 to A3–C4–E4 moves the lower voice up two semitones and the middle voice up one, while E4 stays. Listen across that loop seam by playing Em–Am repeatedly. If you judge only the first three changes, you miss the transition that playback repeats just as often as the others.

Now add A2–F2–D2–E2 on a separate bass track. The upper F clip begins on A3, but the bass supplies F2 beneath it. Puget Sound’s inversion lesson distinguishes root from bass. Name the chord from its harmonic identity, and inspect the whole sounding texture when identifying its inversion.

Each staff represents a separate musical part. The F clip’s lowest note is its third A3; its separate bass is the root F2. Dm and Em similarly place A3 and G3 below their other clip notes while D2 and E2 sound lower still. When those bass roots sound, the combined texture has root-position bass even though the upper chord clip uses inversions.

The worksheet shows both staff and roll versions, plus that independent root lane. Our piano-roll reading guide covers translating between displays. Here use the displays to answer a composing question: which notes can stay while the harmony changes?

Preview of Voice a Chord Loop in MIDI. The two comparison cards let you follow the same pitches in notation and a roll. The lower lane makes the bass-root distinction visible, and the Try it task moves the selected clip and its bass into B minor. Use the full-page comparison to check your own four-bar entry before adding a faster part.

4. Give the chord clip a rhythmic job

Keep Am’s pitches fixed and compare three deliveries: hold the whole chord; play short chords on each “&”; play A3–E4–C4–E4 in quarters. Block & Broken Chords compares simultaneous and successive notes. A repeating cell is an ostinato; The Ostinato gives a keyboard example with a melody above it.

The pitches stay within Am, but each delivery gives the clip a different rhythmic job. Held has one attack lasting the whole bar. Stabs have four attacks between the numbered beats, each lasting an eighth. The ostinato plays one chord tone per quarter-note beat in the order A–E–C–E. Tap four steady beats through all three versions; do not count the held chord as four separate attacks.

Count “1 & 2 & 3 & 4 &” while tapping quarters. The stab version leaves every numbered beat empty and attacks between them. The held version has one attack, even though it occupies four beats. Separate starts from lengths before editing: cutting a note short changes its duration; moving its left edge changes its onset. Ableton’s MIDI editing manual describes these event properties.

For more rhythmic deliveries, Accompaniment patterns uses one progression in several patterns, and Turn chords into grooves asks you to realize accompaniment types. Transfer the idea of a rhythmic role to your clip; you need not copy a pianist’s left-hand layout onto every track.

5. Turn the chord into an arpeggio

An arpeggio presents chord tones successively. Arpeggios: One Hand teaches a playable keyboard version; Arpeggios in Every Key: A minor adds inversions. A device can repeat a selected note order automatically. You can also enter the result manually, which makes the sequence easy to inspect before choosing an arpeggiator.

All four rows draw on A3–C4–E4, fill one bar of 4/4, and use full eighth-note lengths. Their differences come from order, not tempo or available pitches. Our Up–Down has a four-note repeating cycle without doubled endpoints; Up, Down and Input order have three-note cycles. Follow the printed sequence when entering notes manually, and check your device’s endpoint, octave and reset settings before expecting the same result.

Arpeggiator Patterns: Order, Rate and Gate starts with held A3–C4–E4 and compares four orders. Up repeats A–C–E; Down repeats E–C–A. Our Up–Down reverses without repeating endpoints: A–C–E–C. Input order requires actually entering E, then A, then C. A simultaneously entered chord does not specify that sequence reliably.

Choose the order first. Then choose rate, the spacing between starts, and gate, note length as a percentage of that spacing. At 120 quarter-note BPM, an eighth-note rate starts every 250 ms. A 50% gate lasts 125 ms; 25% lasts 62.5 ms. At this eighth-note rate, 50% gate gives a sixteenth-note duration; 25% gives a thirty-second-note duration. The Sixteenth Note teaches the first of those subdivisions. Shortening gate leaves the same pitches and starts. These are MIDI durations; release and effects may extend the audible sound.

Read each rectangle’s left edge before comparing its width. All three rows start the same notes at the same times; only note-off moves earlier. At half gate, 125 ms of note is followed by 125 ms before the next start. At quarter gate, the note lasts 62.5 ms. These lengths describe the MIDI events; the instrument and effects determine how long the sound remains audible.

Check your device’s manual: Ableton documents style, rate, gate and retrigger controls, while Apple’s variation table shows several behaviors under each order name. Our three-note Up cycle crosses beat boundaries: slot 4 returns to A, and slot 9 would be E if it continues without reset. Eight slots still fill 4/4; this is not a new meter.

A three-note cycle and an eight-slot bar meet again after 24 slots: eight repetitions of the cycle, or three bars. That explains why an uninterrupted Up pattern begins successive bars on A, E and C before returning to A. Resetting every bar makes each begin on A instead. Neither setting changes the written meter. Predict the first note of the next bar before listening, and decide which behavior your composition needs.

Use the arp as a separate part, one octave above the close chord clip. For the four chords, sort each selected voicing low to high and repeat its three notes through eight eighth-note slots. In this sketch, restart the order at each new bar. Keep the chord track held underneath initially so you can hear which harmony each busy line belongs to.

The timing diagram uses 120 BPM to make the arithmetic clear; the full sketch returns to 100. At 100, a quarter lasts 600 ms and an eighth lasts 300 ms. A 50% eighth-note gate would therefore last 150 ms. The musical rate stays an eighth note as tempo changes, but its millisecond duration changes. Preserve note values when comparing the composition at different tempos; preserve milliseconds only when that is your specific aim.

6. Write a bassline that supports and answers

Build a Bassline from Chord Roots limits its answers to A1–A2. Use the lowest available root and fifth for each chord: Am A1/E2, F F2/C2, Dm D2/A1, Em E2/B1. Each of our four chords has a perfect fifth, whose pitch class is seven semitones above its root. The selected register can place that chord member below the root. The Bass Clef & the Grand Staff helps locate these low notes.

The roots-only line makes the chord changes easy to hear. The second version keeps those harmonic anchors while introducing each chord’s fifth and a rest on beat 2. The fifth is not always higher than the root in this register: F2 goes down to C2, D2 down to A1, and E2 down to B1. All selected pitches remain within the exercise’s inclusive A1–A2 range.

First sustain only the roots. Then give root–fifth–root the on-beat rhythm: quarter note on 1, quarter rest on 2, quarters on 3 and 4. The rest makes the repeated cell recognizable. Keep the same rhythm as each chord changes; rewrite the pitches rather than moving an entire shape by an unexamined number of white keys.

Now shift those three attacks to 1&, 3& and 4&. Hold the first for one and a half beats, then rest an eighth; play the remaining two as eighths separated by an eighth rest. The tie across beat 2 represents one continuing note. Syncopation helps you maintain the quarter pulse while emphasis falls between it.

The bass answers between the quarter-note kicks. Its first A begins on 1& and continues across beat 2; the tied notehead does not create a new attack there. E begins on 3& and the final A on 4&. Zero shared starts does not mean zero simultaneous sound: the held A can overlap a later kick. Compare onset times when judging the two rhythmic parts.

Put a kick on 1, 2, 3 and 4. Our off-beat bass shares no attack times with it, although the bass can still sound through a kick. That is the distinction to hear: simultaneous starts versus overlapping durations. Try both bass versions against the same kick and choose deliberately. Matching every kick is another option, not a condition of writing a bassline.

For the F bar, say F2–C2–F2 before entering the off-beat rhythm. In a roll, its starts are half a beat after 1, half a beat after 3, and half a beat after 4. Check the first rectangle ends exactly at beat 3; the next half-beat is silent. This separates the pitch task from the timing task, so a correct F chord does not hide a misplaced attack.

The exercise asks for pitches, roll drawings, a wrong-note check and a final Em bar. In its chord-tones-only question, C2 is wrong under Em even though C belongs to A natural minor. “In key” and “in this chord” answer different questions. Use the stated constraint to judge an exercise answer; broader creative choices can include non-chord tones.

Preview of Build a Bassline from Chord Roots. The fixed questions specify range, chord members and rhythm so you can check exact pitches and starts. Its creative task allows more than one answer. Cover the upside-down key while filling the bass names and roll cells, then compare the tied off-beat model with your final Em bar. The quarter-note kick strip is a rhythmic reference.

7. Connect a line, then transpose every part

For one controlled exception, play A3 as a dotted quarter, B3 as an eighth, then C4 as a half note over Am. B lands on 2& and continues upward to C on 3. It is an unaccented passing tone between two chord tones. Non-chord tones compares these visitors, and Puget Sound also shows accented passing tones. Weak placement is our choice here, not their definition.

A3 and C4 belong to Am; B3 connects them by step while the harmony stays A–C–E. The dotted quarter holds A through beat 2, so B begins on the weaker 2& and C arrives on beat 3. The three values total four beats. This is one deliberate non-chord tone with a clear destination, rather than a reason to treat every scale note as equally settled over every chord.

Transpose the pitched arrangement up two semitones: A minor becomes B minor, and Am–F–Dm–Em becomes Bm–G–Em–F♯m. The new collection is B–C♯–D–E–F♯–G–A. Add two to each MIDI pitch number while preserving starts and lengths. UNSW’s pitch reference explains the semitone numbering; Transposition compares interval and scale-degree methods.

Move every pitched note by the same two semitones, including the bass and the arp’s octave-shifted copy. The spellings F♯ and C♯ belong to B natural minor; the chord sequence becomes Bm–G–Em–F♯m. Onsets and durations do not change, so the rhythmic relationships survive. This map uses the held bass-root lane; the lower bass exercise transposes by the same amount into its new B1–B2 range.

Check the less obvious notes: C4 becomes D4; E4 becomes F♯4; B3 becomes C♯4. Move the separate bass and arp too. Leaving one pitched track behind changes the relationships you meant to preserve. The bass exercise’s range becomes B1–B2. Leave the kick’s drum assignment alone; it is providing the rhythmic reference rather than a pitched member of these chords.

Check transposition in both directions. Move the B-minor copy down two semitones and compare it with the saved A-minor original; each pitch number should return, and every rectangle’s position and length should match. This catches an omitted bass note or an arp note moved twice. The test verifies the operation you intended; it does not decide whether the new register suits the instrument you have chosen.

8. Finish an eight-bar sketch you can explain

Return to A minor. Copy bars 1–4 into 5–8, keeping the same chord order. Use held close chords, an eighth-note Up arp one octave above them, and the off-beat bass cell. In bar 8, change only the last arp note from B4 to E5, another Em chord tone. Hear that revised ending lead back into bar 1.

Read each group of three staves together: held chord identity above, moving arpeggio in the middle, and answering bass below. The four-bar chord sequence repeats once. The arp restarts low at each bar, so every bar can be entered independently from its chord’s selected voicing. In bar 8, its final eighth changes from B4 to E5, still within Em. All starts and lengths otherwise match bars 1–4; loop back to the Am opening. The kick is omitted from this pitched reduction; keep its quarter-note attacks on 1, 2, 3 and 4 when auditioning the bass.

There are 32 quarter-note beats in eight bars of 4/4. At 100 BPM the sketch lasts 19.2 seconds before any count-in or sound tail. The figure is a working reduction, not a claim that all tracks need three simultaneous pitched layers. If the arp already states enough harmony, compare a pass with the chord track muted.

Three independent decisions organize the arrangement. Chords establish the harmony and delivery; the arp chooses an ordered line through those tones; the bass locates roots and places attacks around the kick. The panels describe jobs in this exercise, not mandatory track categories. Muting one layer is a useful listening comparison when simultaneous attacks make it hard to hear what each part contributes.

Make each listening pass answer one question: can you follow the root changes, sing the top voice, or clap the bass attacks? If two parts compete, change one register or rhythm before adding another layer. For a separate listening extension, Ear Training: Cadences & Progressions compares phrase endings and other loops; it does not quiz this Am–F–Dm–Em example.

The checkpoint produces two directly comparable versions. Preserve the four-bar original, copy it once, then change a single event at the end of bar 8. Because the last pitch remains an Em chord tone and its time stays fixed, you can listen specifically to the effect of that ending. Test the seam by starting playback in bar 8; starting only at bar 1 can hide an awkward return.

Save both versions and write down the single changed event. You now have decisions you can explain and revise: home, chord identity, voicing, note order, duration and bass rhythm. A Tissimo piano teacher can listen to the sketch in a live lesson and help you hear which part needs more space.

Free worksheets for this lesson

• Voice a Chord Loop in MIDI — compare two voicings and independent bass roots.
• Arpeggiator Patterns: Order, Rate and Gate — read four orders and compare note lengths.
• Build a Bassline from Chord Roots — write roots, fifths and two rhythms.
• The chords of a minor key — compare natural-minor and altered chords.
• The three minors — compare the three C-minor scale forms.
• Scales in Every Key: A minor — fingering and a lower three-form comparison.
• Scale Degree Names — learn degree vocabulary.
• Major & minor — compare thirds above the same root.
• Parallel vs Relative Minor — distinguish tonic and signature relationships.
• Triads & their inversions — identify each lowest chord member.
• Chord symbols — check chord spellings and suffixes.
• Block & Broken Chords — compare simultaneous and successive delivery.
• Arpeggios: One Hand — play a keyboard arpeggio.
• Arpeggios in Every Key: A minor — explore root position and inversions.
• The Ostinato — repeat a pattern under a melody.
• Accompaniment patterns — compare several rhythmic deliveries.
• Syncopation — count between the quarter-note beats.
• The Sixteenth Note — count finer divisions for short gates.
• The Bass Clef & the Grand Staff — locate low pitches.
• Non-chord tones — compare passing and neighboring motion.
• Transposition — preserve intervals in a new key.
• Ear Training: Cadences & Progressions — recognize other loops and endings.
• Turn chords into grooves — write accompaniment patterns.

Sources

• Minor Scales — University of Puget Sound
• Diatonic Chords in Minor — University of Puget Sound
• Inverted Triads — University of Puget Sound
• Passing Tones — University of Puget Sound
• Editing MIDI — Ableton Live Manual
• Arpeggiator — Ableton Live MIDI Effect Reference
• Arpeggiator note order variations — Apple Logic Pro User Guide
• Note names, MIDI numbers and frequencies — UNSW Music Acoustics