SoundCloud (Free)

Record a voice, moment or original music in seconds and share it privately or publicly on Facebook, Twitter, Tumblr and Foursquare. Easily access, browse and listen to the sounds people share with you, wherever you are. The latest app is more social then ever, making it even easier to explore, like and comment on sounds right from your mobile. Share your sounds with the new SoundCloud iPhone and iPad app.

Key Features:

• Record sounds on-the-go and share to SoundCloud, Facebook, Twitter, Tumblr and Foursquare
• Connect with Facebook and easily find and follow your Facebook friends on SoundCloud
• Listen to, like and comment on any of your sounds in the Stream, see comments and likes in Activity
• Browse and search user profiles, and see your followers and followings
• Record a sound now and upload later

Looptastic ($14.99)

Create your own non-stop music groove in an incredibly intuitive way. Combine a huge selection of included loops with your own beats to make a masterpiece. Bend the mix into submission with powerful sound manipulation tools. Share your mixes and performances with the world via SoundCloud!

Looptastic HD 1.7 even lets you sync the BPM (tempo) on two iPads running Looptastic for two Looptastic decks of remix bliss!

GarageBand ($4.99)

Whether you’re a musical prodigy or just love creating your own walls of sound, GarageBand for iPad, iPhone, and iPod touch gives you all the tools you need to lay down fresh tracks and record music anywhere you go. Play a collection of highly expressive musical instruments designed for Multi-Touch that sound and play just like their real counterparts — but let you do things you could never do on a real instrument. Tap out beats on three acoustic drum kits. The snare, kick, toms, hi-hat, and cymbals each produce different tones depending on where and how hard you tap them. Strum chords on acoustic and electric guitars, trigger fingerpicking and strumming patterns, or tap out your own riffs and melodies. Arrange and mix your songs anywhere inspiration strikes using a powerful eight-track recording studio that can handle any combination of audio recordings, Touch Instruments, and loops. GarageBand makes it easy to share your song. Just email it from your iPad, iPhone, or iPod touch. Export and add it to your iTunes library. Or send it to your Mac and open in GarageBand to keep refining it.