UJam is an awesome online, web based music creator. Your music can be shared between students and they can make their own edits to make each jam even better. This is a great site for creating your own music for podcasts, presentations, classroom rap songs, news shows, classroom videos, and more!
One of the coolest features of UJAM is the option to have a student sing freely into the microphone, and UJAM converts their voice into an instrument and creates a song. Meaning, UJAM recognizes the notes you sing, then converts your voice into an instrument hitting those notes. If you want to create an original song, you do not need to know how to read sheet music. All you have to do is sing or hum the way you want the song to sound, then you can tweak it in UJAM!
You can also sing freely into the microphone or to the beat of a metronome, and have UJAM create music to match your song. This is just like SongSmith by Microsoft or the Songmaker APP on iPhone. You sing, then the program creates music to match and go with your own words. It is pretty awesome. Your students will LOVE creating their own songs from scratch.
The site has some very easy to follow tutorials that can help get students started. You can check out the tutorials here. Students can even record their own vocals in their "jam" or create their own songs. I wouldn't put UJAM ahead of Audacity for classroom recordings. However, for browser based music creation and audio recording, you may be hard pressed to find a better alternative.
Students will have to create an account in UJAM so they will need an email address.