The great thing about creating art is that you never have to show it to anyone if you don’t like the way it turns out. Thus, I am not posting a photo of my collage. I hope you have better luck with your Picasso-inspired musical collages.
Cut shapes from your colored papers. You could cut pieces of musical instruments in any colors you’d like or cut music notes. Cut out pieces from your sheet music (do a search for sheet music and print something out if you don’t have any music you can cut up) and use words from newspaper headlines if you want your collage to say something.
Choose what kind of paper you want to use for your background. Picasso often used wallpaper but wrapping paper will work well also. If you don’t have either, tear up pieces of construction paper to make your own background.
Mix a little glue with water to thin it. This will make your paper turn out less wrinkled after you glue it down.
Brush on enough glue to hold the background. Stick it to the poster board. Arrange your collage pieces on top of the background and, when you like the way the collage looks, glue down all the pieces.
You can add paint to your collage, too. Maybe you want to accentuate some of the notes in your sheet music with red paint. Or you could add guitar strings. Use your imagination.