So a few days ago I watched 2 video's by John Frusciante

http://youtube.com/watch?v=mU_sxusyuoI and

The first 4 1/2 minutes aren't really that interesting. You can skip them. He 'teaches' Under The Bridge but it's way too fast to follow. For me at least. After that he starts talking about various types of guitar playing. Really interesting.

What really got me thinking was the part where he talks about why he uses his thumb. I watched it, and again, and again, thought about it a lot, and tried it.

I ultimately decided that using your thumb is more awesome than not using your thumb. As far as I can see, it gives you a lot more freedom to play, as he demonstrates in the video. I couldn't really think of any downside, apart from not being able to use some guitars with like really big necks.

But after some basic logic, I was left confused, because if playing with your thumb was really just better than playing without your thumb, everyone would be doing it. Not everyone is, so there has to be a certain downside to it.

So my question: Is there a downside to using your thumb, apart from not being able to use certain guitars? If so what is it?

Thanks a lot.
Thomas hopes to not have offended anyone with this post. No responsibility whatsoever is taken for any spelling or grammar mistakes, should there be any.

Using your thumb is beneficial in some ways. Such as when you want to use a major chord shape but you want to move your fingers on the higher strings around to add to it. It's a lot easier with your thumb fretting the root note on the 6th or 5th string than it is to barre the whole chord and try and add little melodies with the higher strings at the same time.
If you really are comfortable playing like that, then you should continue with it. You probably will discover some down sides to it if they're are any eventually, thats fine as long as it isn't stifling ability to play.
I want to work in revelations, not just spin silly tales for money.I want to fish as deep down as possible into my own subconscious in the belief that once that far down, everyone will understand because they are the same that far down.
ok try this hold the 3rd fret on your E string with ure thumb. see how far you can stretch your pinkey on the A string, i can get to the 6th fret, now hold the 3rd fret with your index finger, do the same again and you will see you can stretch out a lot futher, its better to play stretched notes than ones too close. as you probbly know the 6th fret on "A" is the same as the first fret on your D string, but if you stretched it you have a lot more lower notes in between plus you can always just go back. altho it is good for playing closer notes, its like an extra finger, the other thing is that you can only really use this methoud on your top E and A strings (or what ever ure tuned to) so there ya go hope i helped
the obvious being that some people dont have the thumb length of someone like froosh or hendrix who used his thumb a lot. For some people its uncomfortable, but if youre comfortable with it, def use it. I use it for a few chords.
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I'm all for using alternative methods to playing, and people creating new styles and whatnot, I just think that I should add, since I didn't see it earlier in the postings, that the strictly proper way to play is with your thumb on the back and center of the neck. that's just the strictly proper way to play, because it makes it easier to extend your fingers so they are coming directly straight down on the fretboard.
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