If I'm not mistaken, you can't really make the songs change each hour, unless you go in and do some tweaks to each song.
To make a playlist of an hours worth of music:
Go to FILE->NEW SMART PLAYLIST.
At the bottom checkboxes, check the box that says "limit to..." and limit it to ONE HOUR by RANDOM, you also might want to uncheck "live updating" if you want your list to forever be the same. Under the conditions, set conditions you would like for your list. You'll want to set "MEDIA KIND as MUSIC" and you'll also maybe want to select only certain genres, or certain playlists, you can set that here using the conditions.
However, the issue arises when making each song play for a minute. You COULD go into each song's properties and make it end the track at 60 seconds, but that is a pain and you'd probably want to set them all back (because if you're not power-houring, it will be a pain later), and that also means your "hour long" playlist is no longer an hour long.
Is there any sort of script that can be made where when a song equals 60 seconds, it goes to the next track? I honestly don't have much knowledge of scripts, but that might work. Sorry I cant help any more.
That said, have fun, but drink responsibly.
