Hello Bogus E.
Not entirely sure if Magic Music/Smartsound is restricted to one hour. Never actually tried stretching out that far. Tended to, if I was using the facility, extend out to about 15 minutes, then use another track for a further 15-or-so minutes, then a third track for another 15-or-so minutes, then, depending on mood, either a fourth track, or reprise the first track out to the end of the video. Assuming I'd be using Magic Music/Smartsound. Often I don't use any music, though in some videos I produce(like New Year's Eve fireworks that I shot, I used four tracks, excerpts from a budget-price LP of moog synthesiser music.
Cheers!
Neil.