Join SOUNDCLOUD, it's the FaceBook for musicians/artists.
You need to start following people that already have a lot of followers. When you post music, it will appear on their page.
You'll start to get followers. It's unlike Twitter, where your followers may never see your Tweets if they follow a lot of people. If you want feedback or listens, you have to be active and give feedback and listens.
There are also groups you can join. If you join a group with a lot of members, you'll start to get followers without having to do much work. People that check the group page may click on the song months later but they'll follow you if they like what they hear.
It's still kind of new and more and more people are gravitating towards using it because it can be integrated into a lot of sites and they have an app for iphone and android.
If people have the app, the songs you put up will be sent to them as a notification. Sometimes I just listen to the songs if I'm burned out on radio.
Some people have 1000's of followers and they leave 100's of comments. It take work to get to that level but SOUNDCLOUD is the most straight forward place to get your music heard imo.
BUT!!! the downside is that most of the people there make music themselves so they aren't casual fans. They're mostly interested in collaborations and feedback on their music if they give feedback on yours.
Where are the casual fans... ? I'd like to know too.