I have a neighbor who made a room in her basement with fabric walls. She stapled the top to the floor joists (?) and I think she used a 2 x 4 on the floor to secure the bottom of the fabric. She actually made a door using a sleeping bag zipper so her cats could not get in. It was a tropical fabric so we called her kids the cabana boys.

For yardage you could probably find top sheets and use your record boxes on the back side of the wall to weight the bottom down.