Nokia HS-20 - Manual (Page 6)

To end a call, press the call key, or use the phone keys.
Listen to music
You can use the headset to listen to music on your compatible phone.
Warning: Listen to music at a moderate level. Continuous
exposure to high volume may damage your hearing.
To play a track, select it in the music player of your phone, and press the
play/pause key (part 5). See the user guide of your phone for details.
To select the next track, press the fast forward key (part 7). To select the
previous track, press the rewind key (part 8). To scroll through the tracks
quickly during playback, press and hold either key.
To pause or restart the music player, press the play/pause key.
To stop the music player, press the stop key (part 6).