In the hobbies collection page (the one that shows all the items collected for the hobby-in this case notes) and at the very bottom, in place of the usual "lucky spin" is "reset the collection". Clicking this will remove all the notes, allowing you to collect them again. Importantly, if you look next to the drum, electric guitar and microphone notes, you'll now see the clip board, light etc. Meaning you need to keep collecting and resetting the collection to gain the required resource for the sign
Took me ages to figure this out! Hth