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

Niacin, Multi-V and Cawfee.  

https://www.youtube.com/watch?v=3gJd27E5X70

I've never used the system to relax except when I was the military and was in the barracks. I had a PS Audio front-end, Adcom 565's and B&W 802's and used to play nature CD's when sleeping. 

I used to have opera tickets and often fell asleep. It was an expensive nap, but a very good one. Listening to music during a nap can be marvelous.

After you've checked your health, you might question what you do all day before you listen to music. I'm home all day and listen to music while I work and also in the afternoon. I hardly ever listen past 4 or 5. I've gotten too tired and know my mind isn't up to music. If I get a jolt of energy at night, I might do an hour or so more work listening to music. 

However, I would not say that falling asleep while listening to music is the worst thing. I think you get a very restful sleep that way.

If you fall asleep listening to The Firebird Suite its definitely narcolepsy.

@audphile1   AQ Coffee--good one!

On a more serious note, as a clinical psychologist who knows about sleep, I would suggest the OP probably has a sleep deficit, so easily falls asleep in the circumstances described.  Poor quality or quantity of sleep becomes common as we age past 60.  A home sleep eval might reveal the source of the problem and could be ordered by the primary care provider.