Yep. All 40 parts of Thomas Tallis's Spem in Alium performed by one guy. I'm impressed, but if you want to hear what this piece can sound like: don't listen to that version. Spem in Alium was written about 440 years ago, requires 40 professional level singers to sing this extraordinarily demanding music a capella. To this day, it is probably the greatest piece of music ever composed by an Englishman (though if Ades is around long enough....). So if you really want to hear how unbelievable this piece can be: listen below....though I've never come across a performance that played this piece slowly enough.