Pearl Jam
The Momma-Son Tape

Here's a little clip from "Pearl Jam 20", the documentary film from Cameron Crowe.
The "Mama-Son" tape refers to the instrumental containing versions of what would become "Once" "Alive" & "Footsteps". Eddie Vedder received the tape from his friend, former Chili Peppers drummer and future short-term PJ drummer (Yield) back in 1990.