Seq66 is a loop based midi sequencer that provides the functionality needed for a live performance. It is a refactoring of the Qt version of Sequencer64 with modern C++ and with a lot of krufty buildup removed. Sequencer64 was based on the classic Seq24, styled after the Akai MPC line, the Kawai Q80 sequencer, or the popular Alesis MMT-8

Major changes:

Non Session Manager: Handles stopping and saving, display of details about the session.

User interface: Using Qt 5 for the user-interface (good cross-platform support) based on Kepler34. Removed the sequencer64 "grid of sets" in favor of unlimited external live grid windows. Added tabs for management of sets, mute-groups, song mode, pattern editing, event-editing, play-lists, and session management. Added a live frame using buttons to match Qt theming, a color for each sequence can be chosen to make them stand out. The Qt 5 GUI is the only official GUI of Seq66.

Configuration files:  Supported configuration files: ".rc", ".usr", ".ctrl", ".mutes", ".playlist", and ".drums" (note-mapping).

Internal: More consistent use of modern C++, including lambda functions. Additional performer callbacks to reduce the need for polling in the user-interface. Seq66 has builds for ALSA/JACK, PortMidi, Windows, and a command-line/daemon. MIDI devices are detected, inaccessible devices are ignored, and playback (e.g. to the Windows wavetable synthesizer) work. It is built easily via Qt Creator or qmake, using MingW.