I agree the mix on Music isn't knockout 4-corner discrete, but given the nature of the music (no pun intended) and that it's a singer-songwriter who plays piano, I think the nature of the mix (lead vocals in all 4, with the piano in FL+FR and RL which I think emulates the triangular shape of a grand piano as seen from overhead) suits it, and gives the music the sense of intimacy it deserves.
I always found those Ode Q8's to be kind of crusty sounding, which I think is especially detrimental to quieter more nuanced music like Carole King's that doesn't saturate the tape with lots of high volume stuff. Like I said, these aren't Enoch Light-style ping-pong quad showoff albums, but they'd really benefit (Music, Rhymes and Reasons and Fantasy, Tapestry is 100% a clang-clang reverb upmix job) from being freed from the shackles of the shortcomings of the QS, CD-4 and Q8 formats via a SACD reissue.