This is very cool! Never knew about the TurboCD ability to play music WHILE playing HuCards!
Yeah, same here. The Turbo Duo is all I ever bought at the nice $99 price cut towards TTi's demise. While this is a nice idea, I dunno if I would've made much use of it had I the option. Don't think I'd care for the extra work to find the perfect track to go with this or that game. Don't have a history of doing that any other time, only for say a project like the Ys titles on the PC and replacing the cheap PC arrangements with the PCE/Turbo versions to play the game in the best possible way!
I think he was simply playing an entire album at a time—that's what I did with lots of consoles/games that got heavy usage (Mario Kart @SNES, Baseball Stars @NES, etc. )
Any game that offered SFX-only (like say, Davis Cup Tennis) would result in a "nicer" experience because there was no in-game music to conflict with the "new music"...
Folks must have been doing this for ages...I was listening to my Walkman whilst playing most PC games (this was before Soundblaster existed). And even during the era of soundcards.