Don Lewis was trained as an electronic engineer and, because of his love for music, he created one of the very early integrated-sound controllers, a precursor to MIDI. In the early 1970s when many electronic musical instruments such as synthesizers were being introduced, performers such as Don found it difficult to access all of the sounds they wanted in a given performance. While some performers pre-recorded the sounds they wanted to use, Don wired all of the instruments together so he could produce those sounds live. His instrument was called LEO, the Live Electronic Orchestra. He built LEO in 1974 and while companies like Roland had programmed their instruments to talk to each other, it would be another 10 years before the manufacturers agreed on the protocol known as the Musical Instrument Digital Interface (MIDI).