It would depend on the context. We have this in english too. With the word "higher" in fact. "Higher, please" could mean height or pitch depending on the context. Languages are confusing.
Mâs performs the same function here as the er ending in English so alto = high, but Mâs alto = higher or louder.
People say this, but it's not actually correct. More plus -er is redundant. I'm not much for correcting colloquial phrases in people's native languages (unless they are paying me since I've done some editing in my day), but since Spanish speakers use "the reverse tree" to help them learn English, only textbook grammar is allowed.