Leo Lab 072, recorded 1999, released 2000 on British label Leo Lab. Total Time: 59 Minutes. Hans Tammen - acoustic guitar, Dominic Duval - bass.

Potlatch P100, recorded 1999, released 2000 on French label Potlatch. Total Time: 67 Minutes. With Denman Maroney - hyperpiano.

As part of 1997's documenta city program, Michael Vorfeld and Hans Tammen created an immersive visual and sound installation in the Kassel planetarium, using the computer-controlled Zeiss 1015 planetarium projector, set against low-tech light sources such as incandescent lamps, fluorescent light, neon light, light boxes, torches, and slide projectors; and a surround sound performance created with a wide array of mechanical preparations (including brushes, small stones, electric fans, cigarette lighters, Ebows and chopsticks) from guitars, and a theremin.

Audio-visual performances with Detlef Landeck – trombone, electronics, loops Hans

HMP CD 12, recorded 1995 on German label Hybrid Music Productions. Total Time: 52 Minutes. Ursel Schlicht - piano & prepared piano, Hans Tammen - endangered guitar