I love Jazz, but deem it their worst 70's album. It definitely transitioned their sound from the early days into their 80's sound. What I love about it is the diversity of their tracks, the experimental aspects of a few songs, and it really does show the value of Roy Thomas Baker, at least to me. It brought back a difficult to describe aspect that peaked with A Night at the Opera before dissappearing during the two albums they produced on their own. I deem If You Can't Beat 'Em, Bicycle Race, Dreamer's Ball, Dead on Time and Mustapha as some of their best.
The only negatives I have with Jazz is that it lacks a real Queen-Classic track like a Liar, Black/White Queen, Lap of the Gods, Bo Rhap, Prophet's Song, Millionare Waltz, Take My Breath Away, WWWRY/WATC
, Spread Your Wings, etc... The best for me is probably Dead On Time, but no track touches the top 2 of any album previously released. I also think John and Roger dropped off considerably after their phenomenal contributions on News of the World.
I still say that Dreamer's Ball would have been a number one hit in the USA. Follow that up with Don't Stop Me know and it would have beaten The Game to number one on the album chart.