Music clearance has been the bane of many TV shows on DVD. CBS/Paramount would often go the route of music replacement and slashing as we saw in a few Five-O episodes (what they did with "The Odd Couple" was criminal in which any time a song line was part of dialogue they would make a cut and so paranoid were they, they even cut scenes of public domain songs! Even a stock music library has caused problems for releases such as how the use of the Capitol Records library for background music on "The Fugitive" led to the infamous debacle of CBS actually hiring a composer to replace ALL of the underscore in Season 2 episodes when fan uproar forced CBS/Paramount to go back and do the show right (CBS/Paramount was even replacing music cues they owned free and cue from the CBS Music Library!) It all depends on the nature of the contracts that existed covering the reuse of music in new video formats. I have read that "Peter Gunn" was a case of a limited license by a small company and not a license in perpetuity that would allow Shout! (who took over Timeless) to be able to reissue the series on DVD. But with Warners and the shows they produced, they want deals where they would have the licensing in total perpetuity so there would be no questions of any legal action in the future and Warners is also rigid in that if so much as one episode from a season has music issues, they won't release. One episode with music issues is why the detective series "Cain's Hundred" was never released on DVD despite streaming all episodes except the one in question. They have streamed a limited number of "77 Sunset Strip" episodes that are free and clear but every season has at least one episode with trouble and likewise "Hawaiian Eye." When "Dr. Kildare" was released on DVD, there was a gap of nearly two years before it's fourth season was released after quick releases of the first three and the reason was clearing all the songs for one episode which involved "the hospital puts on a variety show".

Other Warner shows affected by this: "The Alaskans" (Roger Moore western) and "The Roaring 20s" both of which featured Dorothy Provine and had a load of singing spotlights. Even background music gets impacted by this too and if Cole Porter standards are being played there's trouble there too.

This thread at Home Theater Forum gets into this issue further. The difference with the "Peter Gunn" situation does come up.

https://www.hometheaterforum.com/com...he-60s.367801/