It's easy to forget that composers of past eras had their quirks, their sillinesses and their moments of unbridled humanness. In a letter of June 29, 1778, Wolfgang Mozart's father, Leopold Mozart, tells his wife and son of one of Michael Haydn's less-than-stellar public performances. The episode revealed one of Haydn's moments of weakness, and reminded Leopold and others of the earlier dramatic death of Salzburg organist Anton Adlgasser while at the keyboard. Here's some of Leopold Mozart's letter, in Emily Anderson's translation. "On Holy Trinity Sunday I lunched, as usual, at the priests' house. In the afternoon Haydn played the organ during the Litany and the Te Deum, the Archbishop being present, and he played so abominably that we were all terrified and thought he was going the way of Adlgasser of pious memory. But it was only a slight tipsiness, which made his head and his hands refuse to agree." Wolfgang Mozart responded to his father's letter with a fascinating mixture of frivolity and religiosity. "I had to laugh heartily about Haydn's tipsy it. If I had been there, I should certainly have whispered in his ear 'Adlgasser!' It is really disgraceful that such an able man should through his own fault render himself incapable of performing his duties - at a service instituted in the honor of God - in the presence of the Archbishop too and the whole Court - and with the church full of people. How disgusting!"