That's right, and your Spanish classes were excellent if you remember these details ! The difference is that the phrase "Cuanto le gusta" without the accent would mean "whatever he/she likes" which would make sense in another phrase more complete, for example "He gets whatever he likes" or "Consigue cuanto le gusta".
In the context of a mambo-like song, "Cuánto le gusta" makes more sense, as other usual phrases like "Cómo baila!" or "Cuánto me quiere!"
Please tell me whenever you want any information about Spanish or Latin songs. Cuánto me gusta! :))
Un abrazo - Andrés