Sadly Motown and other black music rarely got a look in. There are imo 3 reasons, racism, the class system and trade unions
Until September 1967 Radio 1 did not exist. The ONLY radio station was called The Light Programme. As an example of how you were dictated to, on a Sunday tea time they had the hit parade. It stopped at 6pm for what we used to call War We War We. In other words a church service (the choir sounded like war we war we :-) )
No pop music was then heard until the next day.
Apart from the lucky few who could get the pirate radio station Radio Caroline, starting at 10pm each night, that was it.
Virtually no black music was played on the Light Programme, maybe Nat King Cole and Harry Belafonte.
Very little black music was played on Radio 1. The Supremes being the only ones I can think of.
The Upper Class ran the BBC and decided what you should hear, not what was new or innovative. How the Stones, never mind black artists, ever got airtime still surprises me.
I mentioned racism, perhaps as the UK was predominantly white they, in their tiny little minds, knew we wanted to listen to white music. That is why UK artists covered black songs and we thought they were the original recordings.
I mention Trade Unions. The Musicians Union would not allow any live performances unless the BBC orchestra was used. Can you imagine the Isley Brothers singing Shout backed by the BBC Light Orchestra ?
As a side note the Musicians Union opposed the introduction of commercial television in 1957 and independent local radio in 1973. Up until Radio 1 they also restricted the amount of records that could be played on the Light Programme. To be fair to the BBC, Radio 1 would have been on air earlier than 67 but the M.U. stopped it.
Finally, sorry for going on for so long, because airtime was so restricted for black artists, what became known as Northern Soul came into its own. The Twisted Wheel in Manchester started as a Soul/Blues nightclub (1963?) before becoming niche with Northern Soul.
I'll shut up now.