” No doubt, the Motown recordings of that time were being done in state of the art studios with the latest multi-track equipment and sound processing gear.”
And studios that were small in size would frequently rent out big rooms at other studios. It was no big deal. Read Sir George Martin’s fascinating book, “All You Need Is Ears.” I does cove a small amount of his career with the Beatles, but is much more his history, and the history of recording. I highly recommend it.
That may account for the "full orchestra" sound on "Papa Was a Rolling Stone" with shimmering strings, a harp and brass. The small quarters of the Motown facility just seem too tiny for everyone to fit in a confined environment. As for the string section in particular, were they likely rented from the local symphony or did they have such players on the staff? Multiple violins were featured on Motown songs of the 60s and early 70s such as "Love Child" and "The Happening" by the Supremes.
Although it took a great while before I got a Round TUIT, I would be remiss if I didn't thank you for this recommendation of last fall. Arriving just last week, “All You Need Is Ears” was indeed a page-turner and a fascinating read. The chapter where he explains sound theory and the math behind music was an eye-opener more aptly, an ear-opener. Martin's explanation of miking the musicians in the studios at Abbey Road was particularly interesting as was his discussion of the "valve" consoles used to mix the microphones. Little did I realize that Martin was far more than the Beatles, with his Parlophone recordings of Peter Ustinov, Peter Sellers, Sophia Loren as well as a whole host of musicians (secular and sacred) from Scotland.
Like you, I heartily recommend the book for anyone even remotely interested in the art -- and science -- of recorded music. Thanks again for a most superb suggestion!