Sight-reading music is the ability to look at a notated piece for the first time and be able to play through it. There are essentially three main scenarios for when you will be likely to sight-read.

1. In the comfort of your own home, when you’re practicing, and learning something new. In this case, learning the piece takes precedence over the actual performance. It’s a good idea to try to initially play it beginning to end, though, in order to get a sense of it.

1. On a gig or at a rehearsal, when an ensemble is given new music to rehearse, record, or even perform. In this case, you’ve got a job to do, so you’ve got to perform something that contributes to the overall group performance.
2. At an audition. Here, all eyes are on you, trying to assess how you perform under pressure.

Depending on the scenario, you might or might not have the luxury to disassemble the music or slow down the tempo, so how you will use the following tips are somewhat dependent on the parameters of the situation. But here are some strategies.

First, though, a general tip: When you receive a music, scan the whole thing, from beginning to end, and look for the first three elements discussed below: repetition, patterns, and hot spots.

Here are some strategies.

1. Look for repetition in the form. Music often contains repeated sections, and if you can spot them, that’s fewer unique things you need to learn. Often, the end is much like the beginning. Look for repetition within song sections, as well as through the whole piece overall. In "Someone Else's Blues" above, we can see that this is a repeating form. If we were sight-reading it in a jazz setting, we'd know that the melody probably sounds on the way in and out, and that the chord progression repeats a few times for solos.

1. Look for patterns. If you can spot a run of notes of the same interval—say, a scalar passage or a series of thirds,  you don’t need to read every note. You can go into auto-pilot and then scan ahead while you are performing the predictable pattern.
   Doing this successfully requires some practice, though. To prepare to do this, you can practice singing or playing interval patterns in isolation. There are really only a few possibilities for how notes follow each other. The next note you play will essentially be either a second, third, or fourth (backwards, a seventh, sixth, or fifth) away. If you have two ore more of the same, that’s a pattern. This is where studying solfege can be helpful. A useful way to practice patterns is by developing the ability to say the solfege syllables very quickly together. Learn these as your mantras, Strive to speak, sing, and play them as quickly and as automatically as you can. It will make spotting interval patterns in the music will become much easier.
               Do Re Mi Fa Sol La Si             Do Si La Sol Fa Mi Re
               Do Me Sol Si Re Fa La            Do La Fa Re Si Sol Me
               Do Fa Si Me La Re Sol            Do Sol Re La Me Si Fa
   Note: Part of a conservatory education includes many semesters of this kind of study. Mastering it doesn’t happen overnight!
   Similar to this, if you can identify theoretical constructs behind the notes, the possibilities for what will be on the page become simpler. In "Someone Else's Blues," we might identify it as a common 12-bar blues form, with a quick IV chord progression in bar 2, and notes drawn primarily from the the C minor and blues scales. Those observations all simplify what we have to play and what we're likely to come across.
2. Identify the hot spots. As part of your initial scan, or while you’re playing the easy parts, see if you can spot any potentially difficult parts coming up, and try to puzzle them out before you get there. Also, strategize how to simplify the hot spot on the fly, so that they don’t derail your performance. If you are reading during a practice session, work on just the hard parts in isolation. When you can finally play it correctly, then practice leading up to it. Then, move on to the next hot spot. In this piece, there's a weird note, G-natural, that occurs in bar 13. It's not difficult, but it is unexpected. Spotting it before we arrive there will give us a better chance of playing it correctly.
3. Silence is better than a clunker—and much better than a swear! If sight-reading is part of a performance (such as an audition, or if you are just playing in front of others), prioritize keeping your place over playing every note. It is better to drop out for a beat and then jump back in than it is to have a train wreck where you have to stop, or to play a terrible note, and then put down your instrument and apologize—or worse, shout a few choice obscenities. Just drop out, or play something simpler but logically fitting, and perhaps make a mental note that this is a spot to practice. Another technique for the practice room is to rehearse recovering from mistakes. One way to do this is to set a timer for every thirty seconds, then start playing. When the timer beeps, drop out for a beat, look away, and then jump back in.
4. Isolate pitch and rhythm. When you are reading during a practice session, you can break down the music before playing it exactly as written. First, play just the rhythms. Then, play just the pitches, in steady rhythm. When you can do both of those easily, put them together.

Reading becomes easier the more you do it. Many musicians find it useful to devote time at every practice session to reading something new. For example, a jazz musician might sight-read through a new chart in The Real Book (many editions now published legally by my co-employer Hal Leonard Corp.) every day. You can also sightread music written for other instruments besides your own, even if the clefs are different that what you're used to. That can be a way to help you break some habits and spot different patterns.

One more tip: Practice being calm and faking competence, when sight reading. There’s the old story of a young dentist joining the practice of an older dentist, who was observing him with a patient. The young dentist slipped, at one point, and  and he said, “Damn it!” Later, his elder took him aside, and said, “Never say ‘damn it’ when you’re with a patient. Instead, train yourself to say ‘There!’”

It’s a lesson for musicians, too. Practice looking calm and cheerful through your mistakes, no matter how badly you botch it. If you don’t show broadcast a failure to accurately render what’s on the page, there’s a good chance that others won’t notice.

Mistakes are instants. What matters more is the overall effect.