Listening to, or studying the grammatical construction of, song lyrics is rarely helpful to learners. Words and grammar structures are chosen to fit the rhythm of the song and singers pronounce words in their own individual style.
See if you can find examples of normal spoken versions of someone saying "find them" and you will get a better idea.
As far as "speak them" is concerned, you will regularly hear this contracted to "speak 'em". In spoken English, BrE at least, we regularly knock the "th" off the front of "them".
- Do the dishes please.
- I'll do 'em later.
- Where are your shoes?
- I can't find 'em.
- Well, find 'em and put 'em on.
I'm exaggerating a little and I'm sure some of the other natives here will tell you that they never do this. In informal spoken English, I certainly do.