There really are no negative aspects of being a great sight-reader. In fact, this is probably one of the most valuable skill sets a musician can have! You’re efficient at learning new repertoire, you’re very hireable as a gig musician, and there’s nothing more satisfying than being able to sit down and just read through some music without having to stop and start all the time. The road to becoming a great sight reader can be a tedious, painful journey, and one I am admittedly still traveling! While the greatest tool for this process is experience and time, there are some things I’ve found to be helpful in speeding up the process.
One of the biggest challenges to sight reading is simply knowing the fretboard. This goes beyond just recognizing the name of whatever note you’re playing and where it is, but also the harmony behind where you are on the fretboard. Knowing every form of D major triad up the neck, and knowing every place you can play a scale in any given key on the guitar is imperative to mastering fretboard harmony. Christopher Berg writes extensively on this topic, and his book “The Classical Guitar Companion” is an excellent resource for studies and exercises.
Another aspect of sight-reading that I found to be challenging is becoming fluent in reading different writing styles across time periods. For example, reading music from the Renaissance Period looks completely different than that of the Classical Period. The multiple voices are written in a more linear, vocal style, whereas music from the classical period is typically much more chordal, usually with a clear melody and accompaniment. I highly recommend reading music across all time periods to really stretch your sight-reading abilities! The Frederic Noad Guitar Anthology is a great place to start, as it is divided by time period and graded by difficulty.
Personally, my biggest nemesis within the realm of sight reading is rhythm. Throw me some sharp-laden keys, weird contortions for the left hand, and I’m fine. However, rhythm beyond basic meter still kicks my butt…and I’ve been at this for over twenty years! I take hope in the fact that I do see improvement in my rhythmic abilities the more focused I am on practicing just counting, and counting alone. It seems like a very simple tip, but you would be surprised at how many well-qualified colleagues have commiserated with me on this topic. Befriend your metronome! It’s like the blunt, sassy aunt that everyone needs in their life from time to time.
My last tip is to find a collection of music that’s enjoyable for you and a little bit below your personal skill level, and just read through as much as you can in one sitting. Set a timer and don’t get hung up on mistakes or technique here, just focus on continuity! Save your hyper-critical, expert guitar player mode for slow practice and learning your main repertoire.
I hope you’ve gained either helpful insight, or at the very least another person to validate your own struggles with the practice!