Miles Davis – A Catalogue of Jazz: Miles Davis

"[Producer Rudy] Van Gelder was one of the first Americans, let alone engineers, to acquire the German Neumann U-47 condenser microphone when it became available in 1949. Van Gelder sought to bring a more intimate sound to small jazz groups. This required placing a microphone closer to the instrument in order to capture the subtleties that traditional recording techniques missed. When Van Gelder initially used the U-47 microphone, he found the sound was easily distorted and unusable. However, a friend of Van Gelder’s, Rein Narma, was able to reconfigure the circuitry of the U-47, making it ideal for close range recording. The result was a detailed, warm sound that many would imitate but few would master. The difference in sound is quite clear when comparing albums Davis recorded with and without Van Gelder.

"Half Nelson" from Davis’ “Miles Davis All Stars” was recorded in 1947 at Harry Smith Studios in New York City. Davis’ talent is undeniable, his vocabulary is progressive, his temperament is wholly his own but—he sounds far away. Davis’ voice exists in the mid range of the mix, and is overshadowed by the shimmer of Max Roach’s ride cymbal and the high end of John Lewis’ piano overtones.

The sound heard on "Solar" from Davis’ album “Walkin’,” recorded in 1955 with Van Gelder, is markedly different: his voice is at the front of the mix, his subtle inflections are captured perfectly. The once intangible details of his playing style are captured, thanks in no small part to a modified U-47 and of course, Van Gelder’s mastery."