Aldrin is an open source modular music sequencer/tracker for the GNU/Linux operating system. It features a flexible audio routing system commonly found in expensive audio software, enabling you to mix, split, mutilate and modify audio signals emitted by software synthesizers and samples.
Aldrin is currently in beta stage, but fully functional. Feel free to try and use it.
If you want to help with testing or building packages, if you are experiencing trouble or if you just want to hang around, you can either visit the forum (preferred) or chat live on #aldrin @ irc.freenode.net.