- acoustic guitars
- classical guitars
K&S Guitars was established in 1990 by George Katechis Montalvo (the K of K&S) and Marc Silber (the S of K&S). They had a combined experience of more than 60 years restoring, repairing, and selling musical instruments. K&S imported guitars from Mexico which were then set up and final-inspected at the K&S headquaters in the Berkeley Musical Instrument Exchange. This was where Mark Silber also had his retail vintage and historical instrument shop. In 1999 K&S split up into two companies: Berkeley Musical Instrument Exchange (George Katechis Montalvo) and Marc Silber Music (Marc Silber).