The bardsong effect from this instrument lasts for one round after the bard stops playing, thus the bard need only sing every other round to keep the effect up continuously. There is neither an extra benefit nor a penalty for playing this instrument every round. It grants the standard +1 To Hit and +1 Damage (or +2/+2 at 5th-level) for bardsong benefits to the party.
Bards may switch to playing a different instrument in the “off-rounds”.