I've been practicing my sight reading for a while and was wondering if anyone had any techniques that I can use to improve at it. I'd also like to know if there are any bad habits to avoid. Also, what are the benefits of getting good at it? Will I be able to learn any piece easily and quickly just by seeing the notes?
You get good at it by doing it a lot! Like anything else, it helps a lot to have a REASON to sight-read. Your friend is studying singing and needs an accompanist. There's a hymn to play on Sunday. Etc.
Getting good at sight-reading lets you do these things! That's why.
No, sight-reading won't let you learn ANY piece quickly. But when a piece is within your technical level, and its musical language is familiar, sight-reading means sight-playing.
There are different levels. There's sight-reading getting EVERY note right. Or there's sight-reading where you play the essence of the music - 'enough to get by'. We're all guilty of this at times :-)
Sight-reading isn't a magic art. It's just like sight-reading a book. It's a natural result of familiarity and experience. But you won't become a fluent reader - of words or music - if you only open a book once a week!
Sight reading is a combination of four skills. When they all come together and are at their relative apex, your sight reading skill will progress. In other words, you can have one without the other but you will eventually hit a wall and go no further.
The first thing you need is an ergonomic technique. If your arms can't play what is written in front of you, having spent decades practicing to sight read won't help. Like buying a car but it doesn't come with tires, it isn't going anywhere.
The second skill is rote which comes with playing a lot of songs. When you play, if you have the ergonomic technique to effortlessly play what is written in front of you, having muscle memory on HOW to play scales and arpeggios will enable you to just play what you think you see in front of you without thought, leading to . . .
The third skill is having a knowledge of music theory. As you read these sentences, you are not looking at every letter. Your brain is seeing key letters and filling in the gaps. Once your brain can instantly recognize scales, chords, progressions and patterns, coupled with technique, your brain will be able to read ahead and make educated guesses. You'll see but not see, you see?
Finally, it requires a trained ear. You must be able to read a score away from your instrument and know what the score sounds like. As you read unknown scores, your ear will lead you. You will know what is coming next.
So combining those four skills will quadruple your reading skills. None in isolation will serve you. It is like never being taught to read or sound out letters. You will be able to speak but the written page would be a struggle. Music has its own vocabulary. Each note, chord or scale is part of that vocabulary.
So the next time you are sight reading and stumble, stop and analyze why. Were your hands unable to get to where they needed to be? Did they not know where to go? Did you ear not know where you were going? Were the notes just individual dots or are they like vowels and consonants forming a pattern and you didn't recognize what it was?
You can't get better by "just doing it." It must be based upon knowledge, effort and skill. If you are not learning something WHILE YOU PLAY, then you may as well just go watch TV. Why play what you know, you already know it. Growth comes from analyzing mistakes and fixing them through knowledge, not repetition. Practice doesn't make perfect, perfect practice . . .
Now, the benefits? You'll know when you achieve it. Like telling a child not to touch a hot stove. They won't learn why until they do it.
Two questions are asked here, how? and why? I'll address the why first.
"what are the benefits of being good at it?" (okay so not a literal WHY). There are many benefits. The first and most relevant is work. If your goal is to be a professional musician then the better you are at reading the more work will exist for you. Studio work, theater work, etc. For these types of gigs you may have to walk in cold are read a score in front of an audience or producers. We almost always get music before for rehearsals but at the very least you'll need to adapt on the fly to conductors revisions. Also, the better you are at reading the less effort you need to prepare for such gigs. Even though you get the score in the mail months ahead of time do you want to spend 8 hours a day for 4 months preparing or a few hours a week?
The next advantage is simply having fun reading. If your reading skills are very bad it might take months to even learn a song whereas if your reading is good you will be able to read through a new tune in the first sitting (it will be messy) and then you can spend more time polishing the work rather than trying to figure it out.
More options for things to play. I see you tagged piano. Guitarists are notorious for being illiterate. TAB is king for young guitar players. I once auditioned for a big band orchestra when I was in my 20s that hadn't had a steady guitarist for a while. The conductor said "I cant' wait to see this". After the audition (and I got the gig) he smiled and said "Holy crap, a guitarist who can read, now I've seen it all". Guitarists these days love TAB so much they refuse to see the value in reading. I always bring up Charlie Parker. Wouldn't you want to play that? Their response is almost always, sure but I can wait for someone else to turn it into TAB. If you can read you can be that person who arranges music for your instrument that no one else plays.
Now to the how?
The best way to get better at sight reading is to do a lot of it. Commit to reading something every day as part of your practice session. I don;t know what it's like for piano players but there are specific issues guitarists need to work through. Be sure you are picking exercises that are not so difficult that you get frustrated but difficult enough to challenge you to focus. Be sure you work from a graded curriculum. I would know exactly what to look at for a guitarist but not a pianist. There are 2 types of reading. If you can figure out the music from SMN then you CAN READ but probably not well. Challenging yourself to read through an exercise with the metronome one and just lay out when you screw up and jump in when you can is a very important training exercise. This is stressed in the guitar curriculum. So if you have already had formal training I'd start by reviewing your old method books otherwise look for something, anything to work out of. If you know how to read but want to get better, get your hands on the greatest variety of sheet music possible and commit to reading a little every day.
There are many questions here already - this will probably be deemed a duplicate. Please read through those questions and their answers.
One of the main benefits is that, when you get really good, there's hardly a need to 'learn' pieces as such. You'll be able to sight read them as if you had learned them. yes, that's quite a distinct possibility. I play with people who've never seen a piece before, and play it, first time, as though they'd practised it forever. But it's taken them years to reach this point.