I decided to do a search on YouTube for “Stairway to Heaven guitar” which is one of the most popular songs guitar students attempt to master. Countless videos appeared. I watched several of them. Each guitarist had a different way of teaching the song. Some videos had really good close-up shots of the fingerboard and others did not. Some of the guitarist played the song very well and others in my opinion played the song horribly.
One interesting insight that I gained through this was that each guitarist had a different way of explaining how to play the song. Some used just basic language like “put your 1st finger on the 5th fret of the 4th string.” Others would say “play an A minor chord in 5th position.” Depending on your level of understanding of the guitar, you may or may not understand what he's talking about, but at least you can see how he is playing it.
I would also like to add an even stronger opinion: I found that many of the guitarists in these YouTube videos were not professionals. Many of the guitarists were playing with some bad habits that they are unknowingly passing on to you because you will certainly pick up these bad habits. Part of the reason that their performances of Stairway to Heaven were so poor, was because they were not playing the guitar with proper technique. Only a professional guitar instructor will be able to teach proper playing technique and only he will know what your weaknesses are and will be able to steer you in the right direction.
I learned the guitar the old-fashioned way. I took a half-hour lesson once a week. My teacher gave me books on chords, reading music, and some other personalized materials, and he sent me off to practice at home until we met again the following week. I would perform the assignments that he gave me, and he would either celebrate my successes or show me where and how I could improve my weaknesses.
YouTube videos will never be able to compete with a competent instructor. If you are seriously interested in learning the guitar, I would take private guitar lessons and use YouTube only as a supplement. YouTube should not be the central source for learning.
What You Can Expect From YouTube
If you choose to use YouTube or any other form of “free” videos, I can give you an idea as to how good you will get on the guitar. You will begin by learning some of your favorite songs by watching a bunch of guitarists on YouTube. As soon as you learn and can play your first song on guitar, you are going to be very impressed with yourself. And you should be. It's certainly an accomplishment. And it was all made possible by getting free instructions from videos on YouTube. Pretty cool.
You might even play your first song for your friends and family members to show them how quickly you are learning the guitar. Then you'll go back to YouTube and learn another song and another. You're going to be amazed at how quickly your progress is on the guitar. It's definitely going to be fun, and it should be. You might end up learning a dozen or more songs on the guitar!
But eventually, you will reach a plateau where you will not be able to improve your guitar skills. You might find a song that you really want to learn, and realize that for some reason, it's too hard. Or that it doesn't sound quite right when you play it. All of a sudden, the guitar is not so much fun anymore. Not only will you think the song is too hard, but you may also know why you can't play it. Or at least, you will think you know why it's too hard.
But if it's too hard, What steps can you take in order to make that song easier to play? That's a tough question to answer. Who is going to answer that question for you? YouTube can't help you. It doesn't know what level you are at. It doesn't know what you are doing wrong. It doesn't know if you have picked up any bad playing habits. And yes, we are all prone to learning bad habits on the guitar or any other musical instrument. Bad habits are ways of playing the guitar that prevent you from improving and being able to play that “really hard” song.
An example of a bad playing habit would be keeping your thumb over the top of the fingerboard will prevent you from being able to play certain things. In the beginning, it's very comfortable to play with your thumb over top of the fretboard because it doesn't feel any pressure. But the thumb is supposed to be behind the fretboard, somewhere in the middle. This can create a lot of pressure on the thumb and hand in the beginning stages of learning. But getting used to it sooner than later will allow you to improve your skills much more effectively. Once you can play the guitar with the thumb behind the fingerboard, then you can “break the rules” and place your thumb wherever you want as long as it helps you achieve what you want to play. This is one of the differences between the pros and amateurs. The pros know when and how to break the rules. But first, you must learn the rules.
It's a lot easier to break a bad playing habit before it actually becomes a habit. Only your guitar instructor can see it before you do.
So just to reiterate for the record, I'm not against YouTube as a learning device. But, I'm strongly against YouTube as the main source of learning the guitar. Use it for fun after you've practiced the assignments given to you from your teacher.