This is a film I go back to every couple of years, remembering how I enjoyed it the last time, and every (re)viewing reinforces my feeling that it is indeed a treat, a delight, a gem.
First, of course, we have the Music. Handel wrote some of the most magnificent "tunes" (as a character calls them in the film) in Western culture and this music is clearly the centerpiece of the film. Although not played on original instruments, it still sounds fantastic and the singing is divine (just watch and listen to young Emma Kirkby in "But Who May Abide" from Messiah - music to die for!)
Secondly, there is the presence (perhaps omnipresence) of Trevor Howard, playing the final moments of Handel as if feeling his own death approaching (he died just two short years later). What charisma this actor had, what magnificent voice, what a mesmerizing performer. Also, it does not bother a bit that Christopher Bramwell plays young Handel in a virtual tongue-in-cheek manner. This only underlines the levity and insouciance of the young composer about to conquer the world.
So what if John Osborne's script is more a reflection of himself than of Handel, as a reviewer previously noted? This is not a filmed biography, but an entertainment and as such, it has few peers. Still, I believe that Handel's love for England was real as indeed there is much to love and admire in that country.
The visual aspects of the film are beautifully done - the costumes, the long shots of cities and palaces, the (probably true) behaviour off and on stage in the 18th century. It all rings true.
So, a witty, literate and well-researched script, sublime music wonderfully performed, great acting and beautiful visuals. What else do you need in a film?