Disco: four on the floor, an octave bass, a string machine and a muted rhythm guitar

Take the loop apart

Press Play and let the eight bars loop a few times. Each row is one track of an Ensemble Set: Drums on T1, Bass on T2, Strings on T3 and Guitar on T4. All four parts are original MIDI written for this lesson. The Ensemble instrument plays them live in your browser, so what you hear comes from the same devices you can edit.

The sections below build the loop up one layer at a time. Use Solo and Mute in the player as you read. Edit sound opens a part's Ensemble editor on this page: turn a knob while the loop plays to hear what it does, or play the keys while the loop is stopped. Reload the page to get the lesson's settings back.

1. Four on the floor and the open hat

Solo Drums. The kick hits every beat of every bar, all at the same strength, and it never stops. That steady pulse is called “four on the floor”, and it is the one thing in disco that does not syncopate. A snare and a clap land together on beats 2 and 4, and a closed hi-hat ticks on each beat.

Between the kicks, on every off-beat (the “and”), an open hi-hat rings out: “tss”. This is what makes you bounce. Each open hat rings for an eighth note, and then the closed hat on the next beat cuts it off, the way a drummer's foot closes the cymbals. The Drum engine works like a real hi-hat here, so a closed hat right after an open one would choke it too soon, and the pattern leaves those sixteenths empty. To hear how much the open hat does, open the project in the DAW and delete the open hats (note 46) in T1's clip: the beat turns into a march.

Two congas add a Latin layer: a low conga on the last sixteenth of beats 1 and 3, a high conga on the last sixteenth of beats 2 and 4. Two very quiet ghost snares (velocity 35) sit just before beat 3 and on the off-beat of beat 4. The sixteenths are swung very slightly (52 %), so every second sixteenth is a hair late, enough to sound played rather than programmed.

Every second bar changes a little: the last open hat becomes a closed hat and a snare pickup on the very last sixteenth leads into the next bar. In bar 8 the kick keeps going, but everything else stops on beat 4 for a short fill: four toms in sixteenth notes, high, high, middle and low, getting louder. The congas and the toms share one sound slot in the Drum engine, so the congas rest under the fill.

2. The octave bass

Now solo Bass and listen to it jump. It plays eighth notes and alternates between the root of the chord low down and the same note an octave higher: the low note on every beat, together with the kick, and the high note on every off-beat, together with the open hat. The bass and the hats bounce as one. This octave bass is the classic sound of disco. Each note is short (a fifth of a beat), so the line stays springy.

The end of each bar is different: on the off-beat of beat 4 the bass plays the low root again, softer, and on the very last sixteenth it plays a passing note one or two half steps away from the next chord's root. G♯ leads back to A, C♯ steps into D, E slides into F and D♯ into E. Bar 8 ends with a quick run up, G♯–B–D, that lands on A at the top of the loop. These stepping stones make the chord changes flow. To hear their job, open the project in the DAW and delete the last note of each bar in T2's clip: the changes suddenly sound abrupt.

3. Rich chords

Add Strings. The progression moves slowly at first, two bars per chord, and then speeds up to one chord a bar:

• Bars 1–4: i9 – IV9 (A minor 9 for two bars, D9 for two bars)
• Bars 5–8: VImaj7 – v7 – iv7 – V7sus4 → V7 (F major 7 – E minor 7 – D minor 7 – E7sus4 turning into E7)

Roman numerals name each chord by the step of the scale it is built on: lower case for minor chords, upper case for major ones. The numbers name the extra notes stacked on top. Disco borrowed these seventh and ninth chords from soul and jazz, and they make even a simple vamp sound lush. The first half is a Dorian vamp: in plain A minor the fourth chord would be D minor, but here it is D major with an F♯. That bright F♯ is the Dorian flavour of a lot of minor-key disco. The second half goes back to plain A minor, with F natural in bar 5.

Look at the strings' notes in the clip: C4 and E4 hold through the first five bars, while the notes around them move by a half or whole step. In bar 8 the chord starts as E7sus4, with A instead of G♯, and halfway through the bar the A drops to G♯. That G♯ is a half step below A, so the loop restarts with a push. The bass plays the roots, so the strings can stay in a tight cluster around middle C.

4. Strings instead of a singer

Most disco records have a big voice on top. This loop has no singer, so the strings take that place. They hold each chord for its whole length and swell in gently instead of starting with a hit, and the long release lets each chord fade into the next. Their sound is wide and shimmering, like the string machines and string sections on 1970s records.

Listen to the end of bar 4: the strings break out of the long chords with a quick run up, A–C–D–E, each note louder than the one before, and land on a high F on top of the F major 7 chord in bar 5. A short run like this is a typical disco hook: it lifts the song into its next section. Solo Strings to hear the run clearly, then play the full loop and notice how it pulls you into the second half.

5. The rhythm guitar

Add Guitar. It plays every sixteenth note of the bar except the ones on the beat, which belong to the kick. On each off-beat it plays a full, loud chord; on the sixteenths in between it plays quiet, very short muted “chucks”. Loud chords and soft chucks together make a busy, ticking pattern that keeps the groove moving even when nothing else changes.

Each chord is a small three-note shape high up, the way a funk guitarist plays near the top of the neck. Most shapes leave out the root, because the bass already plays it, and keep the colourful notes instead: over A minor 9 the guitar plays G, B and C (the 7th, the 9th and the 3rd). In bar 8 the shape changes on beat 3, from E7sus4 to E7, just like the strings. The guitar sits a little to the left, so it does not crowd the bass and kick in the middle.

6. Mix it like a 70s dance floor

Each part starts from an Ensemble factory sound, with a few settings changed for this arrangement. Edit sound shows every value, and the same project opens in the DAW. A value written as 40/127 is the knob's stored number on a 0–127 scale; the editor's display may show it converted, for example as a percentage or a time.

Drums (T1): the Drum engine

The DRUM KIT sound on the Drum engine is a synthesized kit: the STD kit with the PUNCH kick model and TONE at 70/127, slightly bright. Notes follow the General MIDI drum map: 36 is the kick, 38 the snare, 39 the clap, 42 the closed hat, 46 the open hat, 50, 48 and 45 are the toms, and 62 and 64 the high and low congas. DECY goes down from 64/127 to 60/127, so the open hats stay tight instead of washing out. A small reverb send (REV 15/127) puts the whole kit, kick included, a little way into the shared hall.

Bass (T2): Duo, square wave

SQR BASS runs the Duo engine on a square wave through a low-pass filter. The cutoff goes up from 50/127 to 69/127 (about 900 Hz) for a brighter pluck, and RES goes down from 70/127 to 30/127 for round lows. The envelope starts instantly (ATK 0/127), decays over about 300 ms (DEC 79/127) to a sustain of 40 % (SUS 51/127) and releases in 50 ms (REL 54/127), so each note has a bright start and stops cleanly. The MONO voice mode with no glide keeps the octave jumps clean. The bass is completely dry: no chorus, delay, reverb or drive sends.

Strings (T3): Duo as a string machine

STRINGS uses the Duo engine's two saw oscillators. Here they are detuned by 10 cents (DTN 10), and the low-pass filter sits at about 2.9 kHz (CUT 93/127), so the sound is full but not harsh. The attack is 120 ms (ATK 66/127), so each chord swells in; the sustain is at 100 % (SUS 127/127), and the release is about 600 ms (REL 88/127). The chorus send stays high (CHO 60/127) for the ensemble shimmer of a string machine, the reverb send goes down from 70/127 to 35/127 so the hall does not blur the groove, and the delay send is off.

Guitar (T4): Physical, plucked string

PLUCK runs the Physical engine on its STRNG model, a modelled string. BRIT goes up from 72/127 to 95/127 for a bright, clean edge, POS from 40/127 to 25/127 and EXC from 0/127 to 15/127. DAMP goes down only from 84/127 to 72/127 and STRC from 56/127 to 48/127: lower DAMP values stop the string sooner but pull its pitch sharp. The notes sound short and muted because the MIDI notes are short and the release is quick. The Physical engine plays three voices per part, exactly enough for three-note chords. The guitar sends a little to the chorus (CHO 20/127) and the reverb (REV 10/127), and PAN −19 moves it about 30 % to the left.

The set's shared effects

The four parts share the Ensemble Set's Chorus, Delay and Reverb returns, each with its own send amounts. The chorus runs slowly, at about 0.5 Hz (CRT 44/127), with medium depth (CDP 60/127); it mostly widens the strings. No part sends to the delay. The reverb uses the HALL type with SIZE 70/127 and DAMP 55/127. The bass stays completely dry, the drums get only a touch of the hall, and both sit in the centre. A disco mix would usually add a gentle bus compressor on the master; the Ensemble Set has none, so MASTER is lowered from 127 to 112 to leave headroom and LOWCUT stays OFF.

Try this in the DAW

Open in the DAW loads this exact project into the browser studio. The Strings track is selected and armed, and its Ensemble editor is open: play the on-screen keys or your computer keyboard to try your own string line over the loop. Then try these three changes:

1. Disco break: in the Bass, Strings and Guitar clips, delete the notes of bars 5 and 6 and leave the drums alone. Then delete bar 7 in the Strings and Guitar clips too, so the bass comes back first and the rest of the band in bar 8. Hear how a breakdown down to the drums builds tension on a dance floor.
2. Filter sweep: put an Auto Filter (low-pass, 24 dB) on the master and automate its cutoff from 300 Hz up to fully open over the eight bars. The loop starts muffled and slowly opens up, the classic intro trick of French-touch and nu-disco.
3. Modern sidechain: put a Compressor on T3 and feed its sidechain from T1, with a 4:1 ratio, a fast attack and a release of about 120 ms. The strings now duck and “pump” with every kick, a nu-disco sound that the original 1970s records did not have.

Your edits stay in that temporary project. They do not change this page.