c
cowboy@benalman.com
Description:
Currently, Loopy Pro treats time signatures with a denominator of 8 (e.g. 6/8, 7/8, 12/8) the same as their /4 counterparts (6/4, 7/4, 12/4), resulting in incorrect bar lengths and non-musical behavior. For example, a 7/8 bar at 120 BPM should last 1.75 seconds, not 3.5 seconds.
Problem:
  • Compound time signatures (like 6/8 or 12/8) are not interpreted correctly in terms of duration and rhythmic feel.
  • The metronome accenting does not reflect the musical pulse of compound meters.
  • Common groove-based time signatures used in blues, soul, and R&B (e.g. 12/8) are rendered inappropriately, making live performance or composition less intuitive.
Proposed Solution:
  • Implement proper internal handling of /8 time signatures based on eighth-note timing, not quarter-note equivalence.
  • Add automatic or customizable metronome accent patterns based on typical groupings (e.g. 12/8 = 4x dotted eighth, 7/8 = 2+2+3, etc.).
  • Possibly allow users to configure beat grouping/accentuation manually for advanced rhythms.
Benefits:
  • Aligns Loopy Pro behavior with standard musical conventions.
  • Improves metronome usability for groove-based and non-standard time signatures.
  • Makes live looping and composition in compound meters far more intuitive and musical.
Examples:
  • A 6/8 loop plays in two dotted-quarter pulses per bar, not six individual eighths.
  • 12/8 groove (e.g. triplet feel) sounds natural with correct metronome accenting.
  • A 7/8 bar at 120 BPM correctly lasts 1.75 seconds.
This summary was automatically generated by ChatGPT-4 on 2025-06-05.
Original Post:
The Loopy Pro manual says "Loopy does not make use of the denominator (the bottom number). Time signatures displayed as 6/8 and 7/8 are the same to Loopy as 6/4 and 7/4." but I feel like there's an opportunity to improve this behavior and make it more musical.
Problem
  1. Eighth notes are half a beat, so a 7/8 measure at 120 bpm shouldn't be 7 beats * (60 seconds per minute / 120 bpm) = 3.5 seconds long, it should be 1.75 seconds long, because each eighth note is half a beat in length, not a full beat. Contrast that with with Pink Floyd's Money, which is in 7/4. In that case, each of the beats is a full beat, and so a 7/4 measure at 120bpm should actually take 3.5 seconds.
  2. The eighth note value in Compound Time Signatures, where the top number is divisible by 3, and the bottom number is 8 (eg. 6/8, 9/8, 12/8) are often each one third of a beat in length (Blues and R&B music often have this feel). So a 6/8 measure at 120 bpm wouldn't be 3 seconds long, it would be 1 second long. In this feel, a 12/8 measure takes the same amount of time as a 4/4 measure given the same bpm, just as 9/8 and 3/4 measures are the same length at the same bpm.
Note that the Tick Metronome https://apps.apple.com/app/tick-metronome/id1573209073 plugin, when used as an AU inside of Loopy, inherits the time signature (eg. 4/4, 6/8, 7/8, etc) from Loopy as one would expect but behaves very differently from Loopy. It plays each eighth note as half a beat (which is great!). However, that doesn't change the fact that Loopy doesn't play each note as half a beat, so what you'd be hearing as one Tick measure would only actually be half a Loopy measure. Note that Tick doesn't seem to have any way to set the eight note pulse in compound meters to be an eighth note triplet pulse.
Proposed solution
  1. All N/8 time signatures are played such that the 8th note length is 1/2 the length of a single beat
  2. Add an option so that N/8 time signatures where N is a multiple of 3 are played such that the 8th note length is 1/3 the length of a single beat
Benefiits
Better conformity with the general understanding of how Time signatures work, eg. https://en.wikipedia.org/wiki/Time_signature and https://en.wikipedia.org/wiki/Time_signature#Simple_versus_compound
Other notes
In order to properly support Compound Time Signatures, the metronome should output an additional tone to differentiate the main pulse from the triplet subdivisions. Eg. Right now for 12/8 we hear LHHHHHHHHHHH (L = low, H = high pitches) but in order to accentuate the rhythmic pulse, we should hear LHHMHHMHHMHH (L = low, M = mid, H = high pitches).