Formerly used Music Creator 4. Looking for Linux equivalent

[pappygoodwill]

Was running MC4 on Windoze 7. (Yeah, said the "W" word. Don't tell my mother) Had to do a clean re-install. Found out my MC4 CD had apparently slipped off into another dimension. I've got Debian on a Toshiba M45 Satellite and an Acer Aspire One. Time to take my music to the Penguin. What Linux music app should I start with? And which, if any, would read the *.cwp files from MC4? (I save everything on an external drive). I can muddle through most any hardware install/troubleshooting without too much whining for help.