Gene Puerling and Don Shelton had formed part of Puerling's vocal group, The Hi-Lo's some years previously, though Shelton was a 1959 replacement for Hi-Lo's member Bob Strasen. The Singers Unlimited were created to record for commercials, but as time passed they were persuaded to record albums. On the recommendation of jazz pianistOscar Peterson, they signed a contract with MPS Records in Germany. Peterson's trio played on their first-recorded album, In Tune. The group made fifteen albums. Fourteen were recorded for MPS between 1971 and 1982 and were collected in the box set Magic Voices. Puerling's arrangements for Singers Unlimited earned him a reputation as one of the best vocal writers in the world. Members of the vocal group Take 6 often give credit to him and the Singers Unlimited as innovators in a cappella, claiming they "went to school" on his arrangements. Puerling took advantage of cutting-edge, multi-tracking techniques of German studio engineer Hans Georg Brunner-Schwer to create his harmonic concepts and the group's signature sound. In the overdubbing process, baritone Puerling and tenor Shelton would often add two additional middle parts, after which all parts were "doubled" and "tripled." Creating these extra tracks created the fuller, richer sound of the group's recordings. The group would record their songs by having Bonnie Herman record a simplified version of the melody, after which, Len, Gene, and Don would fill in the remaining parts. Once this process had been completed, Bonnie Herman's original melodic line would be replaced with a new one, in which she could add melodic embellishments and add "color" to the group's sound. Bass singer Len Dresslar was known as the voice of the Jolly Green Giant for over 40 years, as well as the voice behind other jingles. He was president of the Chicago branch of the American Federation of Television and Radio Artists for several years in the mid-to-late 1980s. Bonnie Herman was the singer of the original "Like a Good Neighbor, State Farm Is There" commercial jingle, which ran for several years. She is the daughter of Lawrence Welk original Champagne Lady Lois Best and Jules Herman, who was a trumpeter in the Welk orchestra. She is the niece of big band leaderWoody Herman.
