Move your mouse to move the dot. Click to paint the current square that it's on. Hover your mouse near the top to show the 'Color' and 'Brightness' variables, move the slider around to change the appearance of the pixel. Click "Save" to save your drawing, follow the Instructions it gives you. Click "Load" to load an image. press 'z' to skip the current song.
Thank you @Bluefox121 for the idea! Thanks so much to @ggenije for the save code tutorial! Thank you @Will_Wam for one of the songs.