Recitative (soprano): Doch wie erblickt es dich in deiner Krippe
Chorale: Lob, Ehr und Dank sei dir gesagt
Music
[edit]The early-church melody on which BWV 121's opening chorus and closing chorale are based
The opening choral motet is built on a quasi-church modecantus firmus in the soprano, with an archaic effect underscored by a full four-part brass accompaniment.[2] The instruments, other than the continuo, largely double the vocal lines; these and the continuo assume a contrapuntal role.[5] Bach uses fugal techniques and an extended final cadence.[6] It begins in E minor and, unusually, closes a tone higher in F-sharp minor.[7]
The tenor aria is composed as a modern da capo aria, in which the symmetrical scheme is broken up by irregular periodising and harmonization.[6] It includes a very prominent oboe d'amore part.[5] The movement is largely in B minor.[3]Craig Smith remarks that the aria is "marvelously off-kilter".[8]
The third movement is an alto recitative. It ends with a "startling enharmonic progression – a symbolic transformation" to C major.[2]
The bass aria is almost dance-like, playing with the harmony and portraying jumps, reflecting the movement's text's references to John the Baptist's leaping in his mother's womb during the Visitation of Mary.[2] The binary-form string ritornello repeats four times during the aria, framing three separate vocal sections of the da capo aria.[6]
The penultimate movement is a soprano recitative, short and arioso-like.[3] It is remarkable for its extended range.[6]
The closing chorale movement presents the doxology in a four-part setting, illuminating the early-church melody in a modern major-minor tonality.[2] Unusually, the piece ends on a B minorimperfect cadence.[6]
