Learning from mistakes, bad performances

There isn't a performance that is error free, and especially a live performance. It is part of life and it should be taken in stride by performer and listener. It can have unexpected teaching value about the music. I am talking about hearing something I know and, if it seems OK, to be looking at a score during the performance. One learns the pitfalls of a piece, the traps for performer and conductor.

An example happened recently in a performance I attended of the Verdi Requiem. The fun began when a bassoon missed a cue with his entry. The chorus was off a beat having missed its cue with the soloists and it took all a good ten measures to recover. Years ago I had a particularly bad performance of Beethoven's Harp Quartet Op. 74 which sounded awful and clunky but I learned a good deal about the texture in the music, especially the first movement. Sometimes you appreciate a piece that virtuosi make seem effortless in the hands of lesser performers because in the latter's struggles you see the pitfalls and the scaffolding.