The latest version of SongMaker, 2.0.3, was released last month and costs 69p. The app is designed to let you sing over a backing track - some 30 royalty-free tracks are included and you can buy more within the app - and then add harmonies and adjust the pitch.

Backing tracks can also be remixed, though beware - if you have an early-generation iPod touch you'll need an external microphone as the device doesn't have one built in.

Camel Audio's Alchemy Synth Mobile is a free app that turns your iOS device into a synthesiser, featuring a mini keyboard with scalable keys and you can plug in an external Core MIDI keyboard.

However, if you want advanced features such as the ability to export WAV and MIDI files then you'll need to upgrade to the Pro version, which costs £10.49.