Ok, it`s not an article but it`s what I can tell you from the top off my head, in the musical side of things:
Roger: some of his trademarks were demonstrated right from the start:
- Both Modern Times and Loser have very few chords and most of them are major. Check most of Roger`s future work from Tenement Funster to the Electric Fire album and you`ll note he still did that
- Sections over just one chord. Future examples: Surrender, Pressure On, Nazis (so-so)
- One bridge (Happiness, Invisible Man, I`m In Love with My Car, Days Of Our Lives...)
- Riff-driven parts (Fight From The Inside, Man On Fire...)
Brian also started the way he always was: a person of contrasts. Note that from the early days he wrote both ballads (e.g. White Queen) and hard-rock (e.g. Son & Daughter).
In general terms his compositions were based upon simple chords and structures, adorned with great ear-pleasing harmonies. And that was kept from the beginning to the end, from Smile days to Another World.
Some more specific trademarks from him were also incorporated later, such as:
- Pedal bass (KYA, Doin` All Right, later on Hammer to Fall, Las Palabras De Amor, Leaving Home, Teo Toriatte....)
- Canon (KYA, Son And Daughter live, later on Prophet`s Song, Brighton Rock, Now I`m Here...)
- Pentatonic melodies (KYA, later on Dragon Attack, Tie Your mother Down, We Will Rock You...)
Freddie started off as a heavy metal songwriter. He composed more in guitar (e.g. Liar, Ogre Battle) so the songs were harmonically simpler; still he managed to "break the rules" and put weird chords and stuff.
Still it was at the piano where he could achieve his full potential, and songs like My Fairy King or Fairy Feller`s Master Stroke had a very clever harmony indeed.
In those years Mercury specialised in a-cyclic song-froms and very long melodies: Liar, Ogre Battle, Great King Rat, Fairy Feller`s Masterstroke, The March Of The Black Queen. For example, in the last one, after "he`ll bring a little love" there`s a small instrumental connector, and before you know it the key is now Am instead of F. Those kind of "transparent" modulations were what he kept using in the future, for example in Bo Rhap.
Probably the song he learned the most from was Seven Seas, in the matter that as well as being very clever in harmony, melody and form, he managed to keep it "pop" enough to be a hit. And that was his specialty: `We Are the champions` or `Bicycle` are very dense tracks that somehow are "easy to get" and earpleasing, not overwhelming.
An interesting trademark from him is the I>V>vi progression, he used it first in the second album (Masterstroke & Black Queen), then he kept using it for most of the songs he wrote in the piano (BoRhap, champions, Lily, Friends will Be Friends, It`s A Hard Life....)
He also used some variants of the flamenco cadence (which is not only used in flamenco), in Liar and Great King Rat. Futurely Fred would use more variants of that in It`s A Hard Life, Barcelona, Fallen Priest, Bijou, Was It All Worth It, and of course, Innuendo.
There`s much more, but either I don`t remember right now, or I don`t know at all, or I don`t want to get more boring, at least for now :)
John hated Hot Space. Fred's favourite singer was not Paul Rodgers. Roger didn't compose 'Innuendo.' Witness testimonies are often inaccurate. Wales is not in England. 'Bo Rhap' hasn't got 180 voices.