Main Difference
The main difference between Aria and Recitative is that the Aria is a musical piece for a single voice as part of a larger work and Recitative is a musical form in opera, cantata, mass or oratorio.
Aria
An aria ([ˈaːrja]; Italian: air; plural: arie [ˈaːrje], or arias in common usage, diminutive form arietta [aˈrjetta] or ariette) in music was originally any expressive melody, usually, but not always, performed by a singer. The term became used almost exclusively to describe a self-contained piece for one voice, with or without instrumental or orchestral accompaniment, normally part of a larger work. The typical context for arias is opera, but vocal arias also feature in oratorios and cantatas, sharing features of the operatic arias of their periods.
Recitative
Recitative (, also known by its Italian name “recitativo” ([retʃitaˈtiːvo])) is a style of delivery (much used in operas, oratorios, and cantatas) in which a singer is allowed to adopt the rhythms of ordinary speech. Recitative does not repeat lines as formally composed songs do. It resembles sung ordinary speech more than a formal musical composition.
Recitative can be distinguished on a continuum from more speech-like to more musical, with more sustained melodic lines. The mostly syllabic recitativo secco (“dry”, accompanied only by continuo) is at one end of a spectrum through recitativo accompagnato (using orchestra), the more melismatic arioso, and finally the full-blown aria or ensemble, where the pulse is entirely governed by the music.
The term recitative (or occasionally liturgical recitative) is also applied to the simpler formulas of Gregorian chant, such as the tones used for the Epistle, Gospel, preface and collects; see accentus.
Aria (noun)
A musical piece written typically for a solo voice with orchestral accompaniment in an opera or cantata.
Recitative (noun)
dialogue, in an opera etc, that, rather than being sung as an aria, is reproduced with the rhythms of normal speech, often with simple musical accompaniment or harpsichord continuo, serving to expound the plot
Recitative (adjective)
of a recital
Aria (noun)
a long accompanied song for a solo voice, typically one in an opera or oratorio.
Recitative (noun)
musical declamation of the kind usual in the narrative and dialogue parts of opera and oratorio, sung in the rhythm of ordinary speech with many words on the same note
“singing in recitative”