Erfreut euch, ihr Herzen, BWV 66

Bach structured the cantata in six movements. He used the final movement of the earlier work for the opening movement of the Easter cantata: The following four movements remained in the same sequence, the other movements were replaced by a closing chorale. The outer movements are choral, framing recitatives and arias of the soloists, one set of recitative and aria as a duet. Bach scored the work for three vocal soloists (alto (A), tenor (T) and bass (B)), a four-part choir, and a Baroque instrumental ensemble: trumpet (Tr), two oboes (Ob), two violins (Vl), viola (Va), and basso continuo (Bc) including bassoon (Fg).[9] The duration of the piece has been stated as 32 minutes.[10]

In the following table of the movements, the scoring follows the Neue Bach-Ausgabe.[9] The keys and time signatures are taken from the book by Bach scholar Alfred Dürr, using the symbol for common time (4/4).[11] The instruments are shown separately for winds and strings, while the continuo, playing throughout, is not shown.

Movements of Erfreut euch, ihr Herzen

No.	Title	Text	Type	Vocal	Winds	Strings	Key	Time
1	Erfreut euch, ihr Herzen	anon.	Chorus	A T SATB	Tr 2Ob Fg	2Vl Va	D major	3/8
2	Es bricht das Grab und damit unsre Not	anon.	Recitative	B		2Vl Va
3	Lasset dem Höchsten ein Danklied erschallen	anon.	Aria	B	2Ob Fg	2Vl Va	D major	3/8
4	Bei Jesu Leben freudig sein	anon.	Duet recitative	A T
5	Ich furchte zwar/nicht des Grabes Finsternissen	anon.	Aria	A T		Vl solo	A major	12/8
6	Alleluja	Luther	Chorale	SATB	Tr 2Ob Fg	2Vl Va	F-sharp minor

The exuberant first movement was derived from the final movement of the secular cantata.[12][13] It opens with a virtuoso orchestral introduction of 24 measures, depicting vital joy.[14] First the alto shouts: "Erfreut euch, ihr Herzen" (Rejoice, you hearts),[1] the tenor continues "Entweichet, ihr Schmerzen" (fade away, you sorrows),[1] then all voices proclaim in homophony: "Es lebet der Heiland und herrschet in euch" (the Savior lives and rules within you). The middle section is given mostly to alto and tenor, who illustrate mourning and fear in a sorrowful "series of poignant descending chromatic passages and suspensions",[14] although the words speak of the chasing away these moods: "Ihr könnet verjagen das Trauren, das Fürchten, das ängstliche Zagen" (You can drive away mourning, fear, anxious despair).[1]

Incipit of the similar music in Bach's St Matthew Passion

The continuo plays repeated "trembling" notes, a "heartbeat" as Bach would use later in the tenor recitative "O Schmerz! Hier zittert das gequälte Herz" (O pain! Here trembleth the tormented heart).of his St Matthew Passion. Finally the choir enters, one voice after the other building a chord, gently adding words of consolation: "Der Heiland erquicket sein geistliches Reich" (the Savior revives his spiritual kingdom).[1] The instruments throw in motifs of the introduction, leading to the recapitulation of the first section. The movement has been termed "one of the longest and most exhilarating of Bach’s early works".[14]

The bass summarizes in a short recitative, accompanied by the strings: "Es bricht das Grab und damit unsre Not" (The grave is broken and with it our suffering).[1]

The bass continues in an aria, "Lasset dem Höchsten ein Danklied erschallen" (Let a song of thanks ring forth to the Highest).[1] Music in dancing motion complements a general request to thank God in song. The middle section juxtaposes a long note over six measures on "Frieden" (peace) and coloraturas on "lebe" (live).

Movement four is begun by the tenor (Hope), who also wants to sing of victory and thanks ("ein Sieg- und Danklied"). He starts it "Mein Auge sieht den Heiland auferweckt" (My eye beholds the Savior reawakened),[1] with a long melisma showing the reawakening. But already after one measure the alto (Fear) imitates the phrase on the words "Kein Auge sieht ..." (No eye beholds ...).[1] After singing together extendedly, the two different viewpoints are rendered in an argument, termed "a linear discourse as in conventional conversation", ended by the alto trying to believe: "Ich glaube, aber hilf mir Schwachen" (I believe, but help my weakness).[1][14]

In the following duet the voices are homophonic for most of the time, but with little rhythmical differences, showing their different attitude to the darkness of the grave ("des Grabes Finsternissen"): the alto expresses "ich furchte zwar" (I truly fear)[1] on steady long notes, whereas the tenor tells in ornamented figuration "ich furchte nicht" (I do not fear).[1] In the continuation they also deviate only on one word, "klagete" (lamented) in the alto, "hoffete" (hoped) in the tenor. The flowing 12/8 time signature of the duet and a virtuoso solo violin are reminiscent of the original purpose of the music in the congratulatory cantata. It is most fitting for the middle section of the da capo form, when both voices agree: "Nun ist mein Herze voller Trost" (Now my heart is full of comfort).[1]

The cantata is closed by the second part of the hymn "Christ ist erstanden", starting with a threefold Alleluja.[15] It was derived in the 12th century from the Easter sequence Victimae paschali laudes, originally codified by Wipo of Burgundy around 1040. The verses underwent a substantial transformation by Martin Luther with the help of Johann Walter and were printed by Joseph Klug, Wittenberg, in 1533. This is the only use by Bach of "Christ ist erstanden" in a vocal work, but he used the related hymn "Christ lag in Todesbanden" in his early chorale cantata Christ lag in Todes Banden, BWV 4, and in Der Friede sei mit dir, BWV 158.[16]