During my visit to the UK, some of the classes investigated and evaluated a number of music making sites. A number of students have asked me for links to those sites so that they can carry on their work at home.
There are a large number of mixing type web sites available, some of which offer the ability to save, share or e-mail your creations.
One piece of advice... don't forget to use your headphones!
Here are some of the links.
Blobprod Beatbox DJ Mixer
Radio 1 One Studio Sequencer
Radio 2 Songwriting Game
To name just three.
I usually try to avoid linking to sites that require payment, but I have to make an exception for Showmehowtoplay, one of the most effective uses of the internet I've ever seen.
The Multiplayer software that accompanies the site is free to download, but you need to purchase individual tracks to view how each instrument is played. The software allows the user to mute individual tracks in the recording and view solo work in full screen mode. Even if you have no intention of downloading the player, it's worth visiting the site to investigate the artists available. There are also tuition videos for various instruments and the ability to play along with jam tracks with your instrument muted.
There is a junior version available which needs more investigation.