In order to get a thumbs-up from the viewers the instrument/genre combination needs to have at least 4 stars (the very reason why those are highlighted in the chart), any lower will result in a thumbs-down.
Due to limited space, I didn`t include all the instrument upgrades, but the numbers are the same for each upgraded instrument (for example karaoke microphone, professional and dynamic microphone will all have the same genre/instrument results).


Totally unrelated hint: in order to get an A+ for the exams while in mom`s house, you need to study for 14 times.