You can easily search for songs on the interface, and adding them to a playlist is as simple as tapping the button at the top right. You can also add the song to your favorites, as well as to the queue you are playing.
Vanilla Music is a simple, nice, and powerful music player. It's also open-source and has no ads. An excellent application for all those who just want to listen to their favorite songs and not worry about anything else.
Requires Android 4.0.3 or higher