Open a piece of sheet music and look at the five staff lines that contain the notes and all other musical symbols. Understand the staff lines as the backbone of sheet music, where all musical notation is printed.
Look to the left of the staff to see the treble clef, which is where all right-hand notes will go, with some rare exceptions of the left hand playing over the right. The treble clef looks similar to a cursive "S."
Under the treble clef is the bass clef where the left-hand notes can be found. Know that all bass notes have their stems pointed down as opposed to treble notes with stems pointed up. The bass clef looks like a larger comma with a colon to its right.
Learn to memorize the note lines for the treble clef and bass clef. Try the mnemonic device of "Every Good Boy Does Fine" for the notes E, G, B, D, F on the lines in the treble and "FACE" for the notes in the spaces between the lines. Use "Good Boys Do Fine Always" for the bass clef lines and "All Cows Eat Grass" for the spaces.
Take a look at the two numbers you see stacked together to the left of each clef, expressed like a fraction. The top number indicates how many beats you get in a measure, and the bottom number shows the value of the notes in a measure. A 4/4 time means four beats to the measure using quarter notes. A 6/8 time would mean six eighth notes per measure.
Watch for the key signature as a series of flats or sharps stacked together directly to the right of the time signature. Study the different key signatures carefully to understand and develop a natural affinity with the key of any song.
Learn the basic key signatures first. One sharp indicates the key of G major or E minor, and one flat indicates either F major or D minor. Find any minor key by counting three tones down from the major equivalent. C major to A minor would be the most basic example with no flats or sharps.
Determine whether a song is in a major or minor key by looking at the final note of a song. If the song ends on a minor note, then you'll know the song starts in a minor key. Become efficient, though, in deciphering between major and minor from the song's first chord and during key transitions throughout the song.
Read the notes on the sheet music carefully and understand the difference between a quarter note, an eighth note, a half note, and a whole note. A quarter note gets the beat of "1," an eighth note gets half a beat of "1," a half note gets "2" beats, and a whole note gets "4" beats.
Learn the lettered names of each note in a scale. Memorize the scale. Note that after G, the scale begins again at A.
Assimilate the octave scale as C, D, E, F, G, A, B, C. Know that any one of those notes could either be a sharp or a flat depending on the key signature.
Become familiar with many of the musical symbols that indicate dynamics and rests in music.
Understand looped lines over a series of notes as legato for smooth passages and dotted notes as staccato for short, crisp passages. Look for the carrot lines of crescendo and decrescendo, and the symbol of a rest that takes the beat value of a note.
Recognize the symbols representing dynamics and tempo in sheet music. F for fortissimo means loud, and P for pianissimo means soft. Learn the Italian terms for tempo markings, such as "allegro" for fast and "lento" for very slow. You'll sometimes see plain English in pop sheet music intros to describe tempo.