ChirpBox.com... I actually think of a box. A way to speak or chirp. Almost similar to shoutboxes. Could be a service, if thats what you'd want. Music theme fits, as well.. could go usual route with music lyrics or services that have 'been done before'. Definitely a brandable that is memorable, so I'd once again encourage you to make something unique and different to better suit such a nice name. It must be vocal or social. Nice name.. and 2/3rds of the names I see I don't like. I'm very picky.
Your avatar is definitely fitting to what I would envision with the domain; nice. However, music sharing, music services, etc have been done before. Perhaps you can offer something new or offer something necessary to expand on this market.
ChirpBox.com... could be a social network, perhaps, if you'd be interested. Think perhaps a way to connect with others who share the same music interests as you. Birds are a very social creature. They chirp to locate others to mate with and is a form of communication to alert similar birds of their presence. Don't think myspace, friendster, or anything of the like. They are general social friendship networks. Think music. Think of having your own personal 'box' or profile where you can chirp and find that bird that is willing to mate with you or connect with you. Perhaps if you want to meet others like you.. or find someone who could go to the concert you have two tickets for. Make sure you visualize this. I'm a very visual person. I see the site right now as I describe it to you. It could be a social platform for music; both bands and people would be able to connect with each other... not on the general scale that a simple myspace page would give. A place where any bird, anywhere, could chirp and find that someone who has similar music interests. Or perhaps someone who is going to a concert you're going to ("hey, wanna meet up?") and the like. A bird's encounter is not always intimate, it could be a simple call to locate others in the vacinity who are similar. But music itself is a very intimate bond and a strong connection with one's self and people around you. This website could develop into this medium or service that many people (including me) would love to be able to use. There are currently sites such as Pandora.com that find music based upon music you already like using special algorithyms and data. Think of how such services could be expanded upon to a social medium for connecting with those of similar interests both online and off.
Please do PM me so we could chat about this idea and others. I see alot in this name.