I understand that the Levi'im sang in the Bet Hamikdash. Considering that both of them lasted several hundred years, they undoubtedly went through numerous rounds of Levi Singers (sounds like a rock band, almost ;-).
In Tehillim, the word Lamenatze'ach - "For the choir master" is frequently used. This implies that there was a choir and a "conductor". I surmise that the Levi'im sounded quite nice and sang harmoniously. Did they have any rehearsals prior to their singing?
Related - Did every Levi have a turn singing? Didn't some Levi'im have bad voices and were immediately eliminated from being in the choir? (I was in several choirs, but they weren't all Levi'im ;-)
Note: This is not meant as Purim Torah.