Will a 1/2" oak veneered cabinet grade plywood shelf hold 4' worth of CDs in their cases without sagging? This should be approximately 35 pounds total spread evenly over the 4' length, if that helps.

The shelf will be 7" deep and I will attach a skirt (?) (a ledge in the front to help prevent sag and promote strength) to the front of the shelf. This will be attached with 3 biscuits, and glued and clamped.

Or do I need to upgrade to 3/4" ply?

Also, side note: Wanted to drop a thank you to /u/AmishRockstar and /u/zodoor and /u/p2p_editor for answering other questions. I will be posting my first ever woodworking project of built-in bookshelves tomorrow and you guys all helped with the dumb newbie questions.

Thanks all, as always!