320 BPM stands for 320 Beats per Minute. That comes around to the region of 5.33 *beats* per second. Doesnt actually sound that much, but when you take in consideration that The Flight of the Bumblebee is mostly at least 16th notes you get a speed of above 20 picks a second, never mind the possible 32th rolls which i would have to confirm from the note sheet (which i do not posess) Now that’s a little more impressive than the 4 notes a sec quoted in the article.

Here’s the math:

320 beats per minute equals to 5.33 4th notes a minute.
5.33 x 2 to get the 8th’s equals to 10.66 notes a second.
10.66 8th notes a second doubled gives us a whopping 21.32 16th notes per second.

I’m not sure, but there may be 24ths and 32nds which would be about 32 picks per second and 42.62 picks per second respectively.

Fire up the windows calculator and check for yourself.