Techniques are generally described for determining locations of a number of communication devices in a network. The invention additionally provides methods of using such microbial organisms to produce BDO, 4-hydroxybutyryl-CoA, 4-hydroxybutanal or putrescine. The music information service system then matches the CD tag to music data stored in a database. The voltage regulation of the preferred embodiment is performed by a single stage operational amplifier and a two-stage amplifier having Miller compensation. A first series of markings sized and located to show through the second set of openings will indicate the piano keys related to the chromatic scale selected.