annotate PDFs with Preview on Mac OS X

I've been happily practising music using PDFs I downloaded from IMSLP but wishing there was a way to make finger/pedal/stop annotations on them. I discovered recently that Preview in Mac OS X lets you make annotations and save them in the PDF. Tools->Annotate->Add Text in my version. Thought I'd mention it in case it helped anyone else. Cheers!

Another option is a program called piaScore - I use it on an iPad - not sure if it is available for Android or Windows devices. It is an incredible program - and it is free (although there are a few features that require a purchase). You can write/annotate, highlight, white out, type, and add all types of markings/notations to PDF scores. It also has a built in metronome, and a hands-free option for turning pages!

For a free program it is definitely worth looking into. Personally, I haven't had a need to "purchase" any of the extras. The only "downside" is not related to the app, but rather the iPad itself - as the screen is smaller than the average 8.5X11 paper size, the notes are smaller than they would be when printed. For those with eyesight concerns, this might cause a problem. I have heard rumblings that a larger iPad may be in the works for Apple. If true, I will be placing my order as soon as they have a release date!

If any other users here are familiar with piaScore please let me know what you think of it.