In post I would like to cover (in a very brief, *not-in-depth* way) the various ways in which we find written music, how to interpret these various elements in written music, and what the advantages and deficiencies are for each way we see music written.
The types of information that make up a song or a piece of music
Each song we'd like to play will have a few major components we'd need to understand in order to play it.
Rhythm - The subdivision of the beat, or pulse, of the song. In order for us to play a song we'd need to know how to count along with the beat. Is the song in 4? in 3?
Harmony - What are the chords of of the song? Where, in the song, do chords change, and how long does each chord last?
Melody / Lyrics - If the song has words, we'd need to know (more or less) where the words "fall" in relation to the beats of the song and to the chords of the song. We'd also like to know the melody (pitch) and duration of each syllable, and how they relate to the beat.
There are many more factors which we can consider in our playing such as dynamics, articulation, tambor, tempo (how fast we'd like to play a piece of music), instrumentation etc, but we often can infer them based on our existing knowledge of the song. What we often look for first in written music are Rhythm, harmony and melody.