# Disco — Classic 1970s Dance Groove # Reference: Nile Rodgers / CHIC ("Good Times", "Le Freak"), Giorgio Moroder, # MFSB ("Love Is the Message"), Donna Summer ("I Feel Love"), # Bernard Edwards (bass) + Tony Thompson (drums) — the CHIC rhythm section # Disco's defining characteristics: # - "Four on the floor" kick: every quarter note (pos 0,4,8,12) — the heartbeat # that every dancer locks onto. Before disco, the kick was syncopated; disco # made it relentlessly steady to serve the dancefloor. # - Open hi-hat on every 8th upbeat (pos 2,6,10,14) — the "chk-chk-chk" that # defines the era and drove rock fans insane. # - Snare on beats 2 and 4 — standard backbeat, often with a tight, ringy sound. # - The "Philadelphia Soul" variation (MFSB): slightly sparser, orchestral approach. # - Hi-NRG is the Eurodisco accelerated form (Patrick Cowley, Bobby O). # # Three variations cover the main disco sub-styles: # four_on_floor — classic NYC disco: steady kick, open hat upbeats # chic_groove — Nile Rodgers syncopated kick, all-16th hi-hat intensity # philly_soul — MFSB orchestral soul: sparser kick, ride-cymbal pulse # # GM notes: 36=kick, 38=snare, 42=closed HH, 46=open HH, 49=crash, 51=ride # # ── Step grid notation ──────────────────────────────────────────────────────── # Each character in a step grid represents one subdivision of the bar. # Resolution controls how many steps per bar (16 = 16th notes in 4/4; 12 = 16th notes in 6/8). # # X Strong accent — velocity = base_velocity × 1.00 (full hit / downbeat) # x Medium accent — velocity = base_velocity × 0.75 (firm stroke / upbeat) # o Soft hit — velocity = base_velocity × 0.55 (brush / light touch) # g Ghost note — velocity = base_velocity × 0.28 (barely audible, mostly felt) # . Rest — no note fired at this step # # Beat positions — 4/4 at resolution 16 (one char per 16th note): # pos 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 # 1 e1 +1 a1 2 e2 +2 a2 3 e3 +3 a3 4 e4 +4 a4 # (1/+/2/+/3/+/4/+ = quarter beats; e = "e of"; a = "and-a of") # # Swing / feel: the 'feel' field shifts odd-indexed steps (1,3,5,7…) forward in time. # straight — no shift (all steps exactly on the grid) — disco must be machine-tight # ───────────────────────────────────────────────────────────────────────────── name: Disco family: funk bpm_range: [108, 135] time_signature: [4, 4] resolution: 16 feel: straight instruments: kick: { note: 36, base_velocity: 110, velocity_range: 8, timing_jitter: 0.008, duration_beats: 0.14 } snare: { note: 38, base_velocity: 100, velocity_range: 10, timing_jitter: 0.010, duration_beats: 0.09 } hihat: { note: 42, base_velocity: 75, velocity_range: 10, timing_jitter: 0.010, duration_beats: 0.06 } hihat_open: { note: 46, base_velocity: 88, velocity_range: 8, timing_jitter: 0.010, duration_beats: 0.14 } ride: { note: 51, base_velocity: 78, velocity_range: 10, timing_jitter: 0.010, duration_beats: 0.08 } crash: { note: 49, base_velocity: 100, velocity_range: 8, timing_jitter: 0.010, duration_beats: 0.22 } humanization: timing_jitter: 0.010 velocity_jitter: 10 velocity_drift: 0.04 sections: intro: type: count_in hits: 4 note: 42 groove: bars: 1 variations: - name: four_on_floor weight: 3 # The definitive disco groove (Donna Summer, Bee Gees, KC & Sunshine Band style). # KICK: four on the floor — every quarter note (pos 0,4,8,12). This is disco's # non-negotiable law. The steady kick is what made dancers move predictably and # what distinguished disco from funk's syncopated kick patterns. # SNARE: beats 2 and 4 (pos 4,12) — standard backbeat. # HI-HAT: closed on beats (pos 0,4,8,12), open on every 8th upbeat (pos 2,6,10,14). # The closed-open alternation at 8th-note rate is the iconic disco "chk" sound. kick: "X...X...X...X..." snare: "....X.......X..." hihat: "x.x.x.x.x.x.x.x." hihat_open: "..x...x...x...x." - name: chic_groove weight: 2 # CHIC's signature groove (Nile Rodgers / Tony Thompson, 1978–1983). # The kick is more syncopated than pure four-on-floor — it anticipates beats # with an "and-of" pickup (pos 6 = and-of-2, pos 14 = and-of-4) that gives # the groove a funkier forward push. All-16th hi-hat (closed) creates relentless # forward motion. Snare keeps backbeat on 2 and 4 with ghost note on e-of-2 (pos 5). kick: "X...X.X.X...X.X." snare: "....X.g.....X..." hihat: "xxxxxxxxxxxxxxxx" hihat_open: "..x...x...x...x." - name: philly_soul weight: 2 # Philadelphia soul / MFSB orchestral approach ("Love Is the Message", 1973). # Sparser than pure disco — kicks on beats 1 and 3 only, leaving room for the # orchestra. Ride cymbal instead of hi-hat gives a warmer, more melodic tone. # Snare on 2 and 4 with a ghost on the 16th before each backbeat (pick-up ghost # at pos 3 and 11) for a slight human "pre-stroke" feel. kick: "X.......X......." snare: "...gX......gX..." ride: "x.x.x.x.x.x.x.x." hihat_open: "..x...x...x...x." fill: bars: 1 variations: - name: snare_disco_fill # Classic disco drum break: snare on all 4 beats plus 16th pickups — # the "ratatat" fill heard in countless 12-inch remixes before the drop. snare: "....X...X...XxXx" kick: "X...X...X...X..." - name: open_hat_sweep # Open hi-hat on every 16th note — a wash of cymbal leading into the next bar. # Creates the "whoosh" effect common in disco and early electronic dance music. hihat_open: "xxxxxxxxxxxxxxxx" kick: "X...X...X...X..." snare: "....X.......X..." - name: kick_snare_unison # All-16th kick and snare in unison — the "disco stomp" fill that signals # a breakdown or key change. Very dramatic at full velocity. kick: "X.X.X.X.X.X.XxXx" snare: "X.X.X.X.X.X.XxXx" crash: bars: 1 variations: - name: standard crash: "X..............." kick: "X...X...X...X..." snare: "....X.......X..." hihat: "x.x.x.x.x.x.x.x." structure: fill_every: 4 break_every: 0 break_length: 1 crash_after_fill: true dynamic_build: false