Analog audio was first, and video was always analog, but most of the time laserdisc audio playback is literally CD Audio (not merely 16bit/44.1khz but the same intermediate data/error correction/scrambling... even CD-G was recycled into LD-G)

That said, assuming a pilot signal was added one could probably put two to three hours of PAL-frequency analog audio (which completely went away with digital sound) onto a CD.