dynamics
The musical term for a singing voice that vibrates is vibrato. It is produced by rapidly changing the pitch just slightly.
The musical term for "Soft and Sweet" is Dolce.
fermata
agitato
A beat level is another term for the musical beat or meter of a piece.
accelerando
The term you want is 'syncopation'.
dynamics
Rhythm
articulation
ballad
An afterbeat is a musical term for the weaker half of a single rhythmical beat.
A cluster of notes with a similar pattern
You are probably thinking of "syncopation".
The musical term "fermata" refers to how long a note is held. If there is a fermata above the note then the note is held for longer than the usual amount of time.
Metre