Counting 32nd notes is something that I was inexplicably never taught how to do, or at least, never taught how to do accurately. Thankfully, it wasn't hard to figure out on my own using some tools I already had.
This post is aimed more towards intermediate/early advanced players, so feel free to stop reading if you don't fall into either category.
I'm also assuming that you use these rhythmic solfege syllables:
Before I continue, I want to encourage people to stay away from approximating or "feeling" their way through tough rhythms. This terrible advice gets propagated all over the internet, so be wary. With a little work, all rhythms can be learned and performed with accuracy!
I think the ambiguity in counting 32nd notes comes from the lack of clear solfege syllables. Unfortunately, the number-based system only provides syllables up to 16th notes, so what should we use for smaller subdivisions? There are two options:
Apply the syllables we already know to smaller subdivisions.
Learn a new solfege system.
I like option number 1, simply because it's less work and it allows me to take skills I already have and reuse them.
Looking at a measure of 32nd notes, we can see that with 16th note syllables, every other note has no syllable, thus making them difficult to count accurately.
This is how I fix that problem:
I break the measure in half, then reimagine the 8th note as being the note value that gets the beat (not the quarter note). The 16ths can then be counted as 8th notes and the 32nd notes can be counted as 16th notes, thus eliminating the ambiguity and inaccuracy that often comes with playing 32nd passages. Just be sure to avoid adding rhythmic emphasis where it doesn't belong- you don't want your counting method obscuring the written meter.
Here are a few examples from the standard rep:
This Mozart excerpt is a fairly slow 3/4, so I apply the method I described above to count it accurately. Be aware of rushing and unwanted rhythmic emphasis. Check out the second movement of Beethoven 5 for a similar example.
Pickup notes are naturally perilous, especially when they are small note values. For this Shostakovich excerpt, you can accurately place the pickups by subdividing 32nd notes- just make the eighth note the beat and count 32nds as 16ths. The metronome marking I included is Fred Zimmermann's, but it lends itself well to this counting method.
On the topic of pickups, fast scalar pickups like this one are the only times I ever get close to "feeling" my way through a rhythm. I don't necessarily count the value of the pickup notes, but I try to place them based on where they start and end. I do this more at fast tempos than slow ones, obviously.
Other excerpts with studying:
Symphonie Fantasique- mvt. 3 - This excerpt has plenty of 32nd notes and fast pickups.
Beethoven 9 - 32nd notes throughout
That's my crash-course on counting 32nd notes. It's not difficult to do, it just takes a bit of thought, creativity, and patience. Please leave a comment below if you have any questions or want to add anything I missed!