It might be a "mnemonic hallucination" or something, but I seem to remember a letter where Howard was talking about literature one was "supposed" to read that he really didn't care for, and then he veered off using (Gilbert and Sullivan?) as an example of "common/low-brow" music he liked, as opposed to "high-brow" classical, I guess (wonder what he woulda thought of Poledouris? or Morricone?).
You may be thinking of this, from July 1933:
"My tastes and habits are simple; I am neither erudite nor sophisticated. I prefer jazz to classical music, musical burlesques to Greek tragedy, A. Conan Doyle to Balzac, Bob Service?s verse to Santayana?s writing, a prize fight to a lecture on art. I read the wood pulp magazines and enjoy them. I laugh uproariously at slap stick comedy in the movies. I respect men?s religion whether I believe in it or not. I am a 100% American and damned proud of it. I think the United States is the finest country on earth, and I wouldn?t trade a quarter section of it for the whole land of Europe. I cheer and yell madly at football games, prize fights, and horse races. All in all, I qualify, according to the standards of the ?professional intellectuals? as a Babbitt, a yokel, a moron, etc."
In another letter, a couple of months later, he wrote:
"And yet it would be erroneous to say that all radio programs are entirely without cultural value.... Leaving out certain programs which I personally enjoy, but which I realize have no particular esthetic merit, I have heard some things which were not without such merit. I have heard, among other things, such plays as 'The Blue Bird', 'John Ferguson', 'Cyrano de Bergerac', 'Antigone', 'The Admirable Creighton', 'Tartuffe', 'Trelawny of the Wells', 'The Iron Master', and a number of Shakespearean plays. Of course I had rather see these things on the stage, but as my chances of doing that are so slim they are practically non-existant, I was grateful for the opportunity of hearing them over the air. And I am further grateful to the radio for reviving and giving to the world many old folk-songs and legends of the cow-camps, the cattle-trails, and the southern mountains. Then I have heard the music of Wagner, Beethoven, Liszt, and other masters, played by the finest modern musicians, and some splendid recitals of poetry."
So we see that he was not entirely averse to classical music.