

i don’t know popcorn. but i believe you will be able to find a major scale for any instrument with only rudimentary searching.
after that, twinkle twinkle is 1-1-5-5-6-6-5 4-4-3-3-2-2-1 5-5-4-4-3-3-2 5-5-4-4-3-3-2 1-1-5-5-6-6-5 4-4-3-3-2-2-1. sometimes i get fancy and end the last phrase with 2-3-1 instead but if you get comfortable enough with the scale, twinkle twinkle is a breeze.
then in the hall of the mountain king is a great way to work on precision and speed. and i truly believe if you can do that, you can buckle down and learn anything else.
i play trumpet, harmonica, ocarina, penny whistle, glockenspiel (and all other mallet percussion), and guitar. i found piano to be daunting, so maybe this advice specifically is not good for that instrument, and diatonic harmonica and penny whistle both lack some notes that might make in the hall of the mountain king difficult. i don’t know. i didn’t actually learn that tune on those instruments.
but, basically, yes. just do it.
here are some other standards: when the saints go marching in, and somewhere over the rainbow. that one’s fun because it has both an octave jump in it and a phrase with accidentals.
lots of extraordinary claims here, but no proof at all