Under the Half Dome is an album of orchestrated recordings by Ken Allen of the music that he composed while he was at Sierra (as well as some of his favorite scores from non-Sierra games).
There are some really interesting tiers to choose from (enough that the project is included on Forbes' list of the 10 Most Clever Kickstarter Rewards), including a T-shirt with the first page of the handwritten score for "Back to the Sequel", the opening of Space Quest IV at $75, the chance to write 350 words on the liner notes about your love for Sierra's music and/or games at $100, a vinyl edition of the game at $125, actually getting a chance to perform on the recording for "Space Questin" (the ZZ Top inspired song from Space Quest I VGA), and a song written by Ken Allen for you that you are free to use for any family friendly purpose at $1,000 (and much more).
There's links to the some of the original recordings of the songs at the kickstarter page if you don't remember them (but you should, as they're quite catchy) or if you never played the games and want to hear what the fuss is all about, so head over to the Under the Half Dome kickstarter and pick a tier to support the project and help it make it's stretch goals ($20,000 USD for a live recording of "Space Questin" (less than $2,000 USD to go), $25,000 USD for live musicians on key tracks (the tracks in question are specified at the kickstarter), and $35,000 USD for a music video of the band performing Space Questin').
Update: The 24 tracks for the album have been revealed. The full track-listing can be seen here. Also, Ken Allen has put out a call for people to dance to the Space Questin' track for a video he's putting together. Details can be found here (note that the deadline for submitting dancing videos has been extended to February 21, the day that the kickstarter ends).