What are some alternatives?
When comparing Ableton and OpenMPT, you can also consider the following products
NanoStudio - NanoStudio is a recording studio for iOS, OS X and Windows.
MuseScore - 24 Sep 2012 . Design a homepage that captures attention and serves as a good starting point for navigating the website.
AudioKit Synth One - Free & Open-source iPhone/iPad Synth 🎹
Guitar Pro 7 - Create, play and share your tabs
Sampulator - Make (and record) beats on your keyboard
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.