hi diane57! magandang practice yung pagkapa-kapa. it makes your ear more sensitive to recognizing notes. with enough practice magiging oido/owido (ewan ko spelling but it's pronounced oh-weed-ow, hehe) player ka, meaning, you can play by ear, hehe.
isa pang tip, you sing diba? if you sing therefore hindi ka tone-deaf, that's a good thing. eto, try to memorize one note. for example, the A note. by memorize i mean yung you can recognize an A note or chord as you hear it. then pag memorize mo na yun note na yun, it would be easier to recognize other notes in the future kasi you can make your memorized A note as basis for recognizing the notes. gets? example the note is lower than the A note, so most probably G, F, E yan, if it's higher, malamang B, C, D yun. something like that.
pero shempre ang pag-sipra/cipra takes a lot of patience to do so yun, goodluck nalang sa pag-kapa mo ng songs!