There are many alternatives to Ardour for Linux if you are looking for a replacement. The best Linux alternative is LMMS, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Ardour and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Ardour are Reaper (Paid), Bitwig Studio (Paid), Tracktion (Freemium) and Rosegarden (Free, Open Source).
Waveform is a commercial, cross-platform DAW and spiritual successor to Tracktion . With a focus on design and composition, it offers tools to greatly simplify everything from initial inspiration to the final mix.
Renoise is a contemporary digital audio workstation (DAW) based upon the heritage and development of tracker software. Its primary use is the composition of music using sound samples, soft synths, and effects plug-ins. It is also able to interface with MIDI equipment.