The plain Biblical texts of the versions' 'musical accompaniment terms' in their headers and lyrics, came to have been well understood since their translation.
Selah is "come up harder" to have a 'solo' or interlude of the instruments.
As for the range of tune, it is determined by the instruments specified or tone directed, sometimes having a specific interval intended.
The intoning of a text is usually by the words themselves as is still extant in the reciting of a Qur'an.
There is occasionally in the Masorah given 'musical notation' "points", and then there's the ancient now restored science of Chironomy!