Jhani Kaye was of course PD at Coast, and is featured on the JAM “Birth of a Custom Jingle” presentation. When he moved to K-Earth I asked him whether they'd be switching to JAM and he said that Johnny Mann jingles (mostly accapellas) were an integral part of the station sound and he felt he couldn't change them.
But to me the Johnny Mann stuff feels very old fashioned and unexciting.
GB