Related Clues:

• Be at a loss for words?
• Render a tune
• Be a snitch
• Reek
• Run smoothly, as an engine
• Run well
• Sound of tires on the highway
• Machine sound
• Make music, in a way
• Electronic noise
• Substitute for forgotten words
• Sing wordlessly
• Participate without the lyrics
• Sound system problem
• Theme, Part 2