ST. JOSEPH (AP) - The sons of former teen idol Bobby Vee are working to digitally archive his musical legacy before it's lost.

The archiving project includes hundreds of hours of Vee's analog recordings, including cassettes, reels and acetate disks. The conversion to digital began a few weeks ago at the family's recording studio in St. Joseph.

Vee's son Tommy Velline says much of the archive's physical material is nearing the end of its life expectancy.

Vee rose to fame after filling in for Buddy Holly at a 1959 show in Moorhead, Minnesota, after Holly died in a plane crash. Tuesday is the 56th anniversary of the crash that also killed Ritchie Valens and the Big Bopper.

Vee was diagnosed with Alzheimer's disease in 2011.