When I work on my spiccato sound, I liken the sound I try to consistently achieve to looking at the sun...you know, you slowly open up your eyes to see the sun in all its glory and then look away to see a spot in front of your eyes that slowly fades away.

Or something like saying "mwwaaahhh", "mwwaaahh", "mwwaaahh"...no harshness in the sound as the bow makes contact with the string, gets it vibrating, and then lifts up to let the string decay on its own before the pendulum swings back.

I got to hear this sound, and I demanded a claim to that sound for myself.

I'm curious though - is this supposed to be the "ultimate" spiccato sound (and why I enjoy the Karl Beohm recordings of the Mozart symphonies so much), or is there a place in the orchestral world for a popping, aggressive, I've-got-another-bow-handy-if-I-break-this-one-against-the-bout, hammer-on-the-nail spiccato?

I strongly encourage you to discover a great range of tone colours and degrees of "attack" in all of your bow strokes.

I don't think there is ever "one" ideal kind of sound for any kind of bow stroke. Different players and conductors are going to want to hear things different ways at different times. Sometimes things will have harsher edges while other times you'll want a very warm sound.

The bow is a continuum - there are many basic timbres and strokes, but there are an infinite number of points along the way. You might have a few favourite sounds, but try to discover as many as you can. Then you'll be prepared for whatever comes up.

BTW, there certainly are times where you need a very agressive tone and attack (moreso in more modern music), so by all means work on being able to do it if required.

Thanks for the advice. I want to be hopeful and say my teacher is saying something similar by challenging me (constantly) to play an assignment in a different way after I've just played it for him, rather than because I'm simply not following the page...

I got to watch and listen to Paul Ellison make the spiccato sound I tried to describe when he was teaching a master class where the students were playing symphony audition excerpts. I admired that sound immediately, and he seemed to have very clear notions on what kinds of sounds to achieve for the excerpts the players took a shot at. I was lucky enough to have a little cassette recorder on hand to capture him doing it, and so I can review and compare.

I'll keep learning as much as possible about the bow and its capabilities, and work to mirror the interpretations of others. It's fun to see and come to understand how vital the bow's function is to the sound.