Projects are compatible with the equally excellent iOS version, and Logic Pro provides a ready-made upgrade path on the Mac. The effects library includes virtual guitar amps and stompboxes, and there are enough editing and mixing features for you to polish a track to completion. There are plenty of rhythmic and instrumental loops, too - just drag them into the Timeline and start creating - and Apple’s excellent Drummer enables you to create customised drum tracks to fit your projects. Not only can you record audio - your guitar or mic, for example - but you also get a strong selection of software instruments that can be played from a MIDI keyboard.
The most famous free DAW of them all comes bundled with every Mac, and makes it ridiculously easy for pretty much anyone to start making music.