To astound or to enchant

Orazio Gentileschi: young woman playing a violin

Pardon me, if while writing, I shut my eyes and breathe in a few sequences of Vivaldi's 'La Stravaganza, Concerto No. 2' 

There is so much told. There is so much music. And it's packed into ten minutes or so. Try picking a main theme. In fact, listen to the first four minutes and see if you can identify a clear main theme. It's a process, and a continuous one -- this composition.

And then teach your self the art of contrast -- notice the change of pace and information conveyed in the second piece (second movement) at the 4:00 minute mark.
Even here, notice that there is no marked theme. The instrument goes on and on, without reverting to a set tune.

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Now wait; critic Pierre Louis Ginguene said this about Vivaldi's work: "brilliant, difficult and occasionally bizarre passage work", and...

...and picks on La Stravaganza as a specific example of the composer being "more taken up with the cares of astounding the ear than with those of enchanting it". [source]

True? Do you feel that way?

Here's what makes it more interesting: stravaganza in Italian means

• the quality of being new and original (not derived from something else)
• strange and unconventional behavior
• eccentricity that is not easily explained [source]

The composition is meant to astound. So is that quality not enough? The question arises, my dear listeners, can something with great flourishes, that is written to astound, do well without great melody? Must melody be part of this astoundment? Or what Ginguene refers to as enchanting the ear? Do you agree with the critic?

Before you make up your mind, here's what we are dealing with:

• [Musicians and athletes] possess very special skills acquired through years of hard training. No human being is born with the ability to play a violin concerto like Vivaldi's "La Stravaganza", or Chopin's "Quatre Mazurkas" on the piano. [from my notes, source not traced]  

• the La stravaganza set is quite extravagant stuff, full of fantasy and experiment – novel sounds, ingenious textures, exploratory melodic lines, original types of figuration, unorthodox forms. [Stanley Sadie]

• Most movements of Vivaldi concertos go on no longer than a fifties pop hit, but they are packed with information, invention, and emotion; each work is a game of twists and turns, an arrangement of artful shocks. [Alex Ross]

It astounds, it has information; is that enough for you? Astoundment or enchantment [or both]?