There are also a lot of support programs out there to help you grow your business on twitter (and if you are an artist you ARE a business ) such as Hootsuite.com.
You can manage multiple accounts, preschedule tweets, and keep track of how effective your activity is. Honestly, tweet is one of the best things that has happened to media (all forms) in a long time. Take advantage of it and honestly, if you know how to utilize what the net can do to you everything you get done on myspace can happen in the 140 characters of a tweet.