Qtractor is an Audio/MIDI multi-track sequencer for Linux systems.
Qtractor is entirely written on C++ and Qt with its code based on JACK and ALSA. It consists of cool looking graphical UI. It also has built-in mixer and monitor controls, unlimited plug-ins, presets etc.
You can find the complete feature list of Qtractor here.
Qtractor recently released version 0.7.7 with bug-fixes and feature enhancements. Read more about the release changes here.


How to Install Qtractor in Ubuntu, Linux Mint
To install Qtractor in Ubuntu, Linux Mint, run below commands in terminal.
wget https://launchpad.net/~kxstudio-debian/+archive/kxstudio/+files/kxstudio-repos_9.2.2~kxstudio1_all.deb sudo dpkg -i kxstudio-repos_9.2.2~kxstudio1_all.deb sudo apt-get update sudo apt-get install qtractor
Note: The latest release 0.7.7 not yet available in this repo, instead you would get the previous 0.7.6 version.