As far as i know, people don't have much success in running latest Sonar on Ubuntu or linux. I may be

As far as i know, people don't have much success in running latest Sonar on Ubuntu or linux. I may be wrong. Try and see if you could run using WINE.

However there are alternatives. Linux Multimedia Studio LMMS is a free cross-platform alternative to commercial programs like FL Studio®, which allow you to produce music with your computer. See if it fits your needs.