Related Clues:

• Run one's fingers over
• Play with your fingers
• Sing, in a way
• Play the banjo
• Electronic noise
• Pull some strings?
• Strike a chord
• Substitute for forgotten words
• Sing wordlessly
• Participate without the lyrics
• Noodle on a banjo
• Play lightly
• Play, as a uke
• Play, as the ukulele
• Sound system problem