Mastery of Reading Music: Why Intervals, Scales, Chords, and Progressions Matter

1. Reading Notes 

• Obviously you want to start out learning to read notes.  Once you can read notes, you want to practice reading new combinations of notes by sight reading regularly.  Even after you feel comfortable figuring out notes by memorization or using a pneumonic device, you should continue to practice your note reading.  The goal with note reading is developing speed while retaining accuracy.  You should become as comfortable reading notes as you are reading words in your native language.

2. Intervals

• Notes can be read from left to right (melodically) and up and down (harmonically).  Intervals are usually expressed as a number and a minor, major, diminished, or augmented designation.  Reading intervals is all about looking at the space between notes.  Being able to identify and play intervals will enhance your ability to read music as intervals will give you more information to work with.  For example, if I read a chord that is spread out throughout the right and left hands and notice that the harmonic intervals between the notes are perfect fourths; this will allow me to read the chord more quickly than reading and picking out each individual note. 

3. Scales

• Scales seem unimportant to some, but if you know the scale and have mastered the notes it is made of and its fingering, you can play passages of the song more easily.  For example if you spot a scale or piece of a scale in a song, your brain doesn't have to process each individual notes but will rather process it as part of a group.  Once again, you should master your scales instead of just learning to play them one time.  Scales should be a regular component of your piano practice.

4. Knowing Chords

• Chords is another way of reading notes in groupings.  Being able to spot and play chords effectively will increase your ability to learn new material more quickly.  Chords are essentially intervals grouped into even larger groups.  Practicing and identifying chords should also be a regular component of piano practice.

5. Chord Progressions

• The I IV V chord progression is the most common chord progression in music.  Knowing this chord progression and being able to play it in any key will allow you to easily move between the chords when playing a song.  Again, this is another way of grouping note patterns together.  Chords group notes together and chord progressions group chords together.  

How it Fits Together

• Notes are grouped melodically into scales.
• Notes can also be groups melodically or harmonically into intervals
• Intervals are grouped into chords
• Chords are grouped into chord progressions

How Mastery of Reading Music Will Help You

Well, that is an easy answer.  The better you can read music, the faster you can learn, the more accurate your playing will be, and the more enjoyment you will get out of playing.