Sequencer for live or studio sessions
Ableton has had a long reputation for making excellent audio software and Ableton Live is their star app. Ableton Live allows you to manage all the processes of audio production, from beat creation to adjustments, recording and live sets.
Ableton Live features a powerful combination of sequencer and sampler with a library full of instruments, MIDI and audio effects to start working with. Ableton Live offers two sorts of views - arrangement and session. The first being like a traditional timeline, while session allows you to add and play around with effects. For convenience, you can associate any key on your keyboard with any effect, to make the track creation process easier.
Ableton Live includes real-time stretching and warping of audio and even video import to sync audio to video. Although you'll definitely need some technical knowledge to use Ableton Live, it is very well documented with tons of easy to follow tutorials and videos.
Ableton Live is a highly flexible and powerful audio solution for music production. With an excellent interface and a wide library of effects and tutorials, it's one of the most complete and professional music production suites you'll find.