Related Clues:

• Work smoothly
• Pick alternative
• Play lightly, as a guitar
• Use a pick, perhaps
• Accompany musically, maybe
• Indistinct murmur
• Motor noise
• Act the harpist
• Fridge sound
• Insect sound of doubt
• Sound of a bee
• Pluck strings
• Pluck the strings idly
• Sing like a bee?
• Low sound of bad smell?