Why for the life of me I can’t stay awake when listening to Music?

I would also recommend a health checkup, even if just to discuss tiredness levels for one's age and activity.

It could be discovered that the Sleep Pattern contributes to the root cause; 8 Hours and an uninterrupted period of REM are very important. Not achieving this will leave tiredness in its wake. 

FTR, I listen to much more CD now, as I like a little cat nap if it creeps up on me .   

It’s your cables. Get Audioquest Coffee and you’ll stay awake. 

I’m sure, you won’t be always sleepy in live-band cafe.

It’s the listener’s fatigue. The sound of your electric audio system is broken and severely distorted even if you don’t hear it. In fact, our ears and brain hear those bad sound always. They just convert these unlistenable sounds to enjoyable sounds. It’s the trick of human brain which needs 10-100 times more processing work than hearing the natural sound. This is hard work and you become sleepy.

Here’s proof. Your audio system sounds distorted/noisy like the left speaker below. Test your audio system saying "Hello" with your speaker sound like below. Alex/Wavetouch audio

     Electronic sound vs. natural sound

You work too hard!