When receiving external clock, the Play plays on pressing the PLAY button even if it has not received a MIDI START

Bug
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1

Bug Description

MIDI Clock is modal. It is only valid as a synchronization mechanism after a MIDI START or CONTINUE and before a MIDI STOP. Outside these bounds, MIDI Clock serves just one purpose: to get devices “warmed up” to the tempo so that they can hit the ground running when receiving a START or CONTINUE.

The Play is currently violating this MIDI spec rule. If clock is running, pressing PLAY or SHIFT+PLAY will act as a MIDI START even though there has not been one.

This is particularly problematic because it makes it impossible to put the device into Play Chain mode (SHIFT+PLAY) in preparation for a later MIDI START during a performance, if the external clock device is (properly) sending clock for warm-up purposes prior to MIDI START. That is bad.

This is a broken state machine behavior. Instead, Play or Play Chain mode should be MODAL, indicating how the play would respond WHEN receiving a MIDI START.

Proper behavior:

  1. If a MIDI START has not been received, or after a MIDI STOP, Pressing PLAY or at least SHIFT+PLAY should simply toggle whether the Play is in Play or in Play Chain mode when it later receives a MIDI START.

  2. If a MIDI START has been received, pressing PLAY should pause or continue playing. Pressing SHIFT+PLAY should toggle whether the Play is in Play or Play Chain mode and optionally additionally continue playing (but never pause playing).

Steps to Reproduce

Let’s say we’re driving the Play from a Tracker.

  1. Set up a Tracker and a Play but DO NOT CONNECT THEM VIA MIDI.
  2. Set the Tracker Transport and Clock OUT to MIDI OUT and the Play Transport and Clock IN to MIDI IN. Set the Tracker Transport and Clock IN to INTERNAL.
  3. Set up a song on both.
  4. Select PLAY or SHIFT+PLAY on the Play.
  5. Press Play on the Tracker.
  6. At this point the Tracker has sent a MIDI START (which the Play has not received) and is now sending MIDI CLOCK messages.
  7. Attach the Tracker to the Play via MIDI
  8. Note that the Play immediately starts playing even though it has not received a MIDI START.

Occurrence / Frequency

Always

Found in Firmware

  • Version: 1.6.1
  • Build: 1938

Attachments

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Hi @sean-3086 Thank you for reporting this bug. We will do our best to resolve it and notify you when it’s ready. :slight_smile: