Sometimes if I can't understand the lyrics over the music, I'll do a band-pass type filter arrangement with EQ, and cut high and low frequencies, leaving mostly the human vocal range.
A lot of vocal energy is concentrated in the range from approximately 800 - 2000 cycles so I often start by cutting everything else.
I won't say it works great, but it's helped me a few times.
edit to add: I search the web at large for lyrics, but also search some keywords on
https://setlist.FM and
https://Discogs.Com, and browse shows on
https://etreedb.org/ as well, of course, as the archive!