Reading Gramophone magazine a while back, I found an article by Fabrice Fitch called "Forty Voices" in the February 2010 issue. The article concerned the motet "Spem in alium" by Thomas Tallis. The motet ("Spem in alium nunquam habui," or "In no other is my hope") was written around 1570 and is considered a masterpiece of the period.
Fitch notes that the piece calls for eight choirs of five voices."The piece opens with a short melodic idea in a single voice, which is passed to another, then a third, gradually spreading around the choir like a 'Mexican wave.' As more are added, the opening voices drop out one by one, and eventually the wave reaches Choir 8, whereupon Tallis introduces the full ensemble for the first time. This tutti is short-lived, and after a very few bars the Mexican wave begins again in reverse, from Choir 8 back to Choir 1. This second wave is shorter than the first, and after a brief moment of repose on Choirs 1 and 2, the full texture is joined again, this time at greater length. Roughly at the piece's midpoint, the ensemble separates into four groups of two choirs each, tossing ideas back and forth. These interventions get short and shorter, until a cadence is reached." Here, instead of another full choir, a shorter and final Mexican wave ensures, and then the full choir "returns for its longest and final intervention, traverses in several harmonies before alighting on the final sonority as, one by one, all eight choirs come to a standstill" (p. 59).
This fascinated me, so I downloaded the piece. I don't know why I thought I'd get the same effect on an iPod, duh! It's a pretty piece, and I think it would send chills down one's spine in a live performance, but I'll have to wait till someone performs it to get the wave effect.
I'm no musician but I wonder if recordings are necessarily the next-best-thing to hearing a piece live. My daughter's choir, the Summit Choral Society in Akron, OH, performed Durufle's "Requiem" a few years ago, capped with the motet "Tota Pulchra Es." I downloaded those, but I always "hear" them as if the same choir were singing them in St. Bernard's Church in Akron on a spring evening, when tears rolled down my face.