Though I was happy to see Johnny Mercer's song "I'm an Old Cowhand" ranked so high in the Chronicle list of songs about Texas towns and places ["The Top Texas 40," Nov. 28], I have to correct the statement that "Mercer wrote the elegant music and Harry Warren the tongue-in-cheek lyrics." While Mercer did collaborate with Harry Warren (most notably with "On the Atchison, Topeka, and the Santa Fe") and many others, "Cowhand" is purely the product of John Herndon Mercer. Harry Warren was solely a composer and Johnny Mercer was one of the finest of American lyricists. On a few occasions ("Cowhand," "Something's Gotta Give") Mercer wrote both music and lyrics, but he is best known as a top wordsmith.