United DJ is the best way to Explore the music.
This app will automatically crossfade the "Top 200 Songs Trend".
The newest feature of this app is that each song will play small amount of time which will let you enjoy large amount of music with a very excited moment.
You will find out how fast you can seize the trend and spreading your knowledge of various songs and artist.
Its free, give it a try!
If you want to crossfade the local songs, check out Shuffle DJ Mixer: