I begun to play music by following classical music curses. 2 years piano first and after 2 or 3 years guitar. This made me completely unable to play the most simple blues. It took me more than 1 year playing the same 12 mesures blues to finally get it: that's so simple.
I also took 2 years curses into a jazz school. I don't regret it because it gave me a good comprehension of how the occidental music is build. But it was a pytty. I didn't learned music but tricks: on that chord, you can play that scale, and on this one this scale. Bullshit! That's bullshit because a chord is nothing on itself but a few notes vertically arranged, and to get its musical role you must take in account the whole theme with all the instruments or at least the bass, and that both vertically and horizontally.
that's bullshit because you can play one 1 note and keep it a lot of time. It will sound good if it is the right note for that song and you play it with the right feeling. B.B King was an expert of playing so. Also, we all make mistakes. Sometime we play the wrong note, but if you keep playing and succeed to resolve it into the context of the song, we cam make that wrong note to sounds good. Well, not always, it is why practice is so important. It is one of the 2 reasons why I practice everything, chords, scales, rhythms, everything, into the context of a song.
The second reason why I do that is because I hate to practice scales for themselves. I find it completely boring, But I have a lot of fun playing scales or chords or rhythms into a song context. For the scales, most of the time don't ask me what scale I am playing because I just don't know. It was necessary for me to learn a few basic scales first, like blues pentatonic and triads. Pentatonics can be used almost everywhere, and triads are the basis of the jazz arpeggios, with 3 notes (I+III+V), you know what you play and they will always sounds good. For the other notes, like with the blues chords, just use your feeling. Another useful thing is to know the basic substitutions you can make. The first blues songs was on 1 chord, and just by making chords substitutions and introducing V-I, II-V-I and VI-II-V-I chords progressions, they made it to the jazz over the years. Beside that, what one will need most to learn to play is to practice.
Rhythms are also very important. I like to practice most of my songs with different rhythms, tempos and signatures. For me, the magic rhythm is the cuban son. It comes from the Yoruba culture of Senegal and its basis, the clave, is a 2 bars rhythm made of 2 different rhythms. For the guitar, the best tutor I know for that rhythm is here: https://www.youtube.com/watch?v=Y3if5ME5gGo
He show different ways to play it. I practice it everyday with any kind of songs or chords, and found other ways to play it as well. Also, if you simplify it by removing the strokes on the guitar, this allow to play it 2 times faster and you will be playing punk music or something like that.
Also memory is something amazing. It was many years ago, we was playing on a blues with some buddies, I play a solo with my guitar, and at the end of the solo, I realized I just played the melody of the Ravel's Bolero. It just fit, and the most amazing is that I played that song on the piano before, but never played it at the guitar. And it just went out and fit on that blues at that moment.