I haven’t been down lately — a little overworked, yes — but I’m still enjoying this downer of a tune from Bloc Party called Talons.

When people think of rock “opera,” they usually mean 20-minute songs. But this is operatic in style without demanding that the listener clear out a day to listen.

The most obvious interpretation of the song is a fable about AIDS, though that’s not necessarily the only interpretation. More broadly, it’s about guilt and death. The protagonist and his circle of friends have led entertaining but reckless lives, and they’re suffering the consequences.

What separates it artistically from the typical emo music is the change of moods. The verses are full of subdued regret. The chorus cries out against the same circumstances, dialing up the anguished self-loathing. “I have been wicked / I have been arrogant.”

The best part is the bridge, a final bit of defiance. “I didn’t think it would catch up as fast as I could have run,” they sing over a major key progression that sounds almost Wagnerian. Then they modulate back to the minor for the crushing line — “a new disease came in the post for me today.”

If you don’t buy all the aesthetic talk here, just know that it rocks. Enjoy.