However in your case if the score is searchable and “Horns” is at the same position on each page (you may need to prep those that are not in an OCR editor)
Simply add “horn” to the search box and press enter rather than next page at the required time
Now for the impossible (OR when the score is not OCR’d)
At each zoom level in “NON” continuous mode (Ctrl6) SumatraPDF will allocate the same position on each page to a given number of page down commands, thus you may notice say 4 or 5 positions while the sidebar is active
Now for the fun part (may require a little experimentation)
Using “Mouse and Keyboard Centre” for Microsoft hardware (I am using version 3.2 on win 7 or 8 but beware some versions not suitable on win 10 home)
OR any other macro software (such as AutoHotKey)
you can set a number of page downs here I have added 2 at a time = half a page to my wheel mouse (you may depending on normal zoom level need say 4 in your case to get to the same location on each page)