Sequencer64 is a live MIDI looper with a song-creation layout window. Sequencer64 is a reboot of seq24, extending it greatly over the last six years. The heart of seq24 remains intact. It is an old friend with a whole lot of added equipment. It has an extensive manual and Windows installers. Sequencer64 has build options for ALSA, PortMidi, JACK, Gtkmm 2.4, Qt 5, Windows, and a command-line/daemon.

github.com/ahlstromcj/sequencer64