ISTR reading in an IRS pub on non-profits (No. 557, I **think**) that you can automatically claim 501(c)3 if your org's annual income is under $5000 a year, without having to file. Filing is required only if your income is over $5000 or if you have an actual need for the letter of determination to show someone.
I can actually see both sides in this debate. I understand NMPA's position; they're afraid we won't buy their artists' songbooks if we can get the lyrics here for free. OTOH, even if I can get someone's lyrics off the web, I **still** would usually need the songbook for the chords (and the tune!).
This is also why I'm going to be real careful about getting permission before I post that song the Getaway folks want me to post. The people who have the rights to that particular one are also **very** protective of their rights.