A number appended to a letter is understood by LilyPond to indicate that particular note's note-value. A whole note is indicated with a 1, and all other durations are indicated with a number representing the fraction of a whole note that they occupy: half notes are 2 (like "1/2 note"); quarter notes are 4 (like "1/4 note"); eighth notes are 8 (like "1/8 note") and so on.

To add a "dot" to a note (thereby increasing its length by one half), you simply include a period after the number. For example, e4. means "dotted quarter note on E."

To add a "tie" from one note to the next (thereby continuing its duration across a measure-line), add a tilde ( ~ ) after the pitch and duration.

After indicating a duration, it is assumed that all subsequent notes have the same duration, until indicated otherwise.