"Quando me'n vo" or Musetta's Waltz is one of the most popular and beloved arias by Puccini. It is in the core repertoire of many singers, pianists, coaches, and conductors. Puccini's music is known for a wide range of rubato (literally meaning "stolen time"). Even this aria sounds pleasant to sing, play, conduct, and listen to, it's full of rubato, but not without a proper pulse.
Your Operaoke Challenge is to tap on the music stand or baton according to the pulse (in 3/4) you hear throughout this rendition sung by Mirella Freni conducted by Vladimir Ghiaurov in Munich in 1987.
Start tapping at the moment you hear her first note sung. A conductor's job is to lead the singer. If you see text matching hers, you are behind. The key of this Operaoke Challenge is to be like a prompter, who is always a beat ahead.
At the end of the aria, a percentage will show according to how well you have accomplished this tricky job of coordination. Good luck!
(Tips: there is a one measure of 4/4 in the middle of the aria.)