You can use Siri (iPhone 4s or later) or Voice Control to control music playback. See Make requests and Voice Control.
Use Siri or Voice Control. Press and hold the Home button.
Play or pause music: Say “play” or “play music.” To pause, say “pause,” “pause music,” or “stop.” You can also say “next song” or “previous song.”
Play an album, artist, or playlist: Say “play,” then say “album,” “artist,” or “playlist” and the name.
Shuffle the current playlist: Say “shuffle.”
Find out more about the current song: Say “what’s playing,” “who sings this song,” or “who is this song by.”
Use Genius to play similar songs: Say “Genius” or “play more songs like this.”