Favorite song to demo or test drive speakers?

Sir Adrian Boult conducting The New Philharmonia Orchestra in Holst's The Planets, on E.M.I.

Trevor Pinnock performing numerous Rameau Harpsichord works, on CRD Records (UK).

The Missing Linc by Lincoln Mayorga And Friends, The Sheffield Drum Record, the Sheffield Track Record. Direct-to-disc.

A Meeting By The River by Ry Cooder and V.M. Bhatt, on Water Lily Records.

The first two Paul Simon albums.