They didn't say that, maybe they can read both Arabic and musical notation.

The replied to comment seemed skeptical to treat musical notation as text. But any reasonable definition of "text" should include musical notation.

Otherwise it would be hard to include other types of obvious text, including completely mainstream ones such as Arabic. They are all strings of symbols intended for humans to read.

Feel free to disagree but I don't understand the argument here, if there is any. Lots of people read both Arabic and musical notation, it's a completely normal thing to do.

any reasonable definition of "text" should include musical notation

Then many a dictionary must be unreasonable [0]:

  text
    1. A discourse or composition on which a note or commentary is written;
       the original words of an author, in distinction from a paraphrase, annotation, or commentary.

    6. That part of a document (printed or electronic) comprising the words [..]
  
    7. Any communication composed of words

    n 1. the words of something written

Musical notes do not form words, and therefore are not text. (And no, definition 1 does not refer to musical notes). The written down form of music is called a score, not a text.

[0] e.g. http://dict.org/bin/Dict?Form=Dict2&Database=*&Query=text

Anything that can be turned into a string programmatically is by definition text.

I agree with you, I am disagreeing with the one that replied to you.