I made a program to make music! It tells you what note you will place, and it also has four instruments: the piano, the guitar, the trombone, and cello. Put your mouse over a note and hit the d key to delete that note, right arrow key to make the note longer, and left arrow key to make the note shorter (doesn't work if the note is short as possible). You can also hit the c key to clear all of the notes.
I found the drawings for the piano, guitar, trombone, and cello online, and colored in the trombone, and piano myself. 3 loves and favorites, and I will make it scrolling! (So you can make it longer).