Release 1.2.1 of Hydrogen is the new stable release of Hydrogen. It fixes a number of bugs and inconsistencies found in version 1.2.0 and is generally recommended for all users.


  • Update French translation


  • Fix reopening of last used Playlist. In addition, in case the PlaylistDialog was opened at the end of the last session - when “Reopen last used playlist” is checked in the Preferences - the dialog will be reopened too at the same position.
  • Fix spurious marking of opened songs as modified.
  • Fix MIDI (output) feedback for metronome toggling and pan setting.
  • Fix superfluous MIDI event - Action bindings. An incoming MIDI event can be mapped to an Action only once.
  • Fix tool tips of MIDI-learnable widgets. All bounded MIDI events will be shown.
  • Fix MIDI note output for channel 16 (previously only channel 1-15 were accessible in the InstrumentEditor).
  • Fix spurious tempo changes to 120bpm when switching songs or between pattern and song mode (#1779 and #1785)
  • Support “START”, “CONTINUE”, and “STOP” type System Realtime MIDI messages in PortMidi and CoreMidi.
  • Fix MIDI action binding to incoming MMC_DEFERRED_PLAY event.
  • Fix missing MIDI driver restart when adjusting corresponding parameters in Preferences.
  • Fix MIDI Machine Control (MMC) event type handling on Windows (#1773)
  • Fix loading of legacy drumkits. All layers but the first one were dropped during drumkit upgrade (#1759)
  • Fix MIDI input handling with “Discard MIDI messages after action has been triggered” checked. Incoming NOTEON message were dropped without triggering a sound (#1751)
  • Fix beat and bar calculation in pattern mode (#1741)
  • Fix compilation in GCC with -Werror=format-security (#1739)
  • Explicit usage of Python3 in script
  • Fix build against Musl (nekopsykose)
  • Omit git commit hash in displayed version of release builds

Source code and binary releases for Windows and macOS are available from GitHub.