This is a worksheet I use after students learn notes A and B on recorder. Not only does it allow them to compose but it also solidifies their new recorder skills.
I explain to students that each box represents a beat. Their job will be to create a 16-beat rhythm. We discuss that since each box is a beat, each box could have a quarter note, 2 eighths or a quarter rest. If it is brought up by a student, I do allow them to draw a half note over 2 boxes or a whole note over 4 boxes. I ask them to draw beautiful notes with dark note heads. Then I ask them to write A or B under each note head, but tell them they are not simply allowed to alternate between A and B.--I explain that would be a boring composition. I also create a sample composition (mine) on the interactive whiteboard so that they are very clear on what to do. I allow students to play through their compositions on their recorders to see if they like what they wrote and if they want to change anything. I tell them to ignore the bottom of the page and then turn it in.
We discuss how to draw notes A and B on the 5-line staff. I explain that now they are going to take their composition from the boxes and put it on the 5-line staff. They need to hear me say that it should be the SAME. I notate an entire example (my composition) on the board, carefully pointing out that each line of boxes or 4 boxes is a measure and they need to draw a barline after 4 beats. I also ask them to draw a double bar at the end. As students work to notate their composition, I circulate around the room and try to make sure everyone understands what is to be done.
I ask students to play through their compositions and list themselves as the composer and then also decide on a tempo marking and title for their piece. I list about 5 common tempo markings on the board and explain each one. They often all want a fast tempo and I advise them a fast tempo only works if their composition sounds musical when played fast or if it fits the title AND if they can accurately play it fast. We discuss where to write the title, tempo marking, and composer.
I pick a few compositions that were done neatly and sound nice and I play them for the class. I then put students in groups of approximately 4s and give them about 25 minutes to create an arrangement of the recorder composition with unpitched percussion and dance or drama if they want. You can decide how much freedom you want your students to have in your classroom. My only rule is that at least 1 student in the group must play the composition on recorder. I've had a lot of interesting arrangements over the years. When there are 5 minutes left of class, I have each group perform their arrangement and I insist that all students act as respectful audience members: All instruments not being playing must be on the ground with hands off.