A mathematician by training, he acquired a devoted following with songs that set sardonic lyrics to music that was often maddeningly cheerful. Tom Lehrer, the Harvard-trained mathematician whose wickedly iconoclastic songs made him a favorite satirist in the 1950s and ’60s on college campuses and in all the Greenwich Villages of the country, died on Saturday at his home in Cambridge, Mass. He was 97. Lehrer’s lyrics were nimble, sometimes salacious and almost always sardonic, sung to music that tended to be maddeningly cheerful. Accompanying himself on piano, he performed in nightclubs, in concert and on records that his admirers...