I can't address enough how important music theory and ear training are for students of any musical instrument or any genre. Without you having good foundation with music theory or being able to "HEAR" (ear training) you'll soon get stuck on the same plateau for a long time. Think about ear training. Isn't music about listening sound? So, you need to be able to HEAR well. That's why listening is a big (huge) part of playing music. And theory also helps you to hear and understand what's going on in the music better. With the good solid foundation of music theory you'll expand and do more things than just play a few songs. Not only you'll be able to be a good "player" on your instrument, you'll also be able to compose, arrange, dictate, & transcribe. Theory and ear training also help musicians to play with other musicians better. So, if you would like to be a good "player" or good musician as a whole I would recommend you to spend 50% of your practice time or energy into theory and ear training. You may say, "What? 50%? That's too much". But, yes, 50% ! Just try it for a while and see if you see a good result. Find a good teacher who can teach music theory and give you ear training. Ear training is something that you have to do with a teacher. You can't teach yourself. But if you can't find a teacher I would check this website: It's an online game site for music theory and ear training. Visit: Theta Music Trainer. That may be fun for younger folks. And another one (not gaming) that I recommend for learning music online is Berklee Online. They have a free trial for theory and ear training without registering in the entire course.