We really have to rethink what our notion is of academic "basic skills". A basic skill is not reading or writing, but rather "hearing" and "seeing" by the brain, which has other names in educational circles, like phonological awareness, sound segmentation, sound discrimination, visual tracking, or visual-orthographic skill.
There's a lot of good news for children and adults who struggle with reading and learning English, but first they need to be educated that the problem is not with 'being smart' or having a good memory, but rather that their mind's 'ears' and / or 'eyes' are not yet automatically tuned to hearing the same sounds, or seeing the same letter strings as fluent readers. This has importance for children as well as adults, and for primary Spanish- or other language-speakers trying to learn English as a Second Language.
The figure below is from a Stanford group which found that musicians had an easier time distinguishing differences between word syllables. What you do, rewires your brain.
Music is not the answer for every one's problem with phonology, but it makes sense that for some, musical training will help them to better hear some of the 'quick' sounds of spoken words - like for instance "water" instead of "walter."
Musical training helps language processing
Language, music, syntax, and the brain
11 Million in U.S. Illiterate in English