We all listen to different types of music for many different reasons but mainly the reason would be dependent on your mood and as luck would it there is an app made just for that. This is Moodagent originally found on iTunes, but it has now been released for Android.
Simply press the Moodagent icon and it will come up with a list of tracks that matches the mood of the music that the user is currently listening to. It is an easy way of getting the music you want when you want it. The Moodagent app is priced at £0.75 or $0.99 and can be downloaded from Google Play for Android and iTunes for iOS powered devices.
Source: Mood Agent