Hi Ian,
The use of the same footage was a cop out. You're right, the 'Burning" programme seemed like a repeat of the Motown programme at times. With the size of the BBC's budget you'd have thought they could have researched the Motown programme better too. The early days of Gordy's move into music were completely absent. No mention of Billy Davis, Marv Johnson, The Satintones/Voicemasters, Anna or any other of the building blocks that led to his initial foray with Tamla. I suppose the programme was aimed at the general public and they relate the Motown logo to the Big 5. It was well presented, but lacked a lot of essence. Sort of 'glossy' but not enough info.
One point about the SITSOM documentary though is that the programme wasn't about the original vocalists, (I'm not sure if you're correct about them declining - I was under the impression that Slutsky didn't want the vocalists involved as it would then just become yet another documentary about them and not the musicians). I think SITSOM acheived it's aim of enlightening people about the band but the omission of Mike Terry and Popcorn Wylie still leaves a huge gap in the story of "The Sound Of Young America". Still enjoyable though, for sure.
Enjoyed the history of MC5 and The Stooges too.