I have been playing Sweet Leaf purely by ear and and have worked out all the rhythm parts in it. However, listening to the solo it seems like Iommi does a lot of legato and I could be wrong but does he use delay in the studio version? what I am trying to say is it's very hard to make out the notes in the solo. So, what should I do? Should I just come up with my own that sounds good and play it?
I've learned a few solo parts by ear before, but i would record them with a DAW, Ableton Live specifically, then slow it down and follow the notes at that tempo. It's not as easy as it sounds though because the frequencies warble a lot, as if the sounds get pixelated by slowing them down.