FourTrack by Sonoma Wire Works could be just the right app for a singer/songwriter who’s working on the demo of his or her breakout hit. The app lets you capture musical ideas anywhere using the iPhone’s built-in mic or the headset mic. You can also install it on the iPhone Touch and capture music via a third-party mic. As the name implies, you can record four separate tracks with independent volume and pan controls. The app stores multiple song files, and allows you to upload the files to your computer using the iPhone’s browser and a Wi-Fi connection to your computer. Each track of a song is its own file, so once you upload it to your computer, you’ll need to rebuild the song in your favorite audio editor (like Audacity). This is an early foray into multi-track iPhone recording. We can only expect it to get better.