I actually made these trees last year and never blogged about them.
I covered some foam trees from the hobby store with glue and glued on burlap and crochet trim for the big one.
The middle sized one is covered with burlap too and I printed out the type filled keys font on card stock and glued them on.
The smaller tree is covered with glue and sheet music paper.
To top them off I bought some little stars at the craft store that have little stems.