Prince Johann Ernst of Saxe-Weimar

Johann Ernst of Saxe-Weimar (German: Johann Ernst von Sachsen-Weimar) (25 December 1696 – 1 August 1715) was a German prince, son by his second marriage of Johann Ernst III, Duke of Saxe-Weimar. Despite his early death he is remembered as a collector and commissioner of music and as a composer, some of whose concertos were arranged for harpsichord or organ by Johann Sebastian Bach, who was court organist in Weimar at the time.

Johann Ernst was born in Weimar, the fourth son and sixth child of Johann Ernst III, Duke of Saxe-Weimar, and second child of the Duke's second wife, Charlotte Dorothea Sophia of Hesse-Homburg. As a young child the prince took violin lessons from G.C. Eilenstein, who was a court musician.

He studied at the University of Utrecht between February 1711 and July 1713. It is thought that Johann Ernst furthered his understanding of music at this time. From Utrecht, he could visit such centres as Amsterdam and Düsseldorf and it is known that he had copies of Italian music sent back to Weimar. (Household bills for the year from 1 June following his return record the cost of copying, binding and shelving music.) In particular, it is thought that he might have encountered Vivaldi's opus 3 set of violin concertos. The prince's interest in collecting music was sufficiently well known that P. D. Kräuter, when requesting leave of absence to study with Bach in Weimar, mentioned the French and Italian music that the prince was expected to introduce there. Kräuter also praised Johann Ernst's virtuosity as a violinist.

On his return from university, Johann Ernst took lessons in composition with a focus on concertos from the local church organist Johann Gottfried Walther, a cousin of Bach. Walther had previously given the prince keyboard lessons and had given him his Praecepta der musikalischen Composition (Precepts of Musical Composition) as a twelfth birthday present.

During his life, Walther transcribed seventy-eight concertos for keyboard. Bach also produced a number of virtuoso organ (BWV 592–6) and harpsichord (BWV 972–987) arrangements. These included some of the prince's own works (BWV 592, 592a, 595, 982, 984 and 987) as well as works by German and Italian composers, including Georg Philipp Telemann (BWV 985) and Vivaldi (BWV 972, 973 etc.). The Bach transcriptions were created roughly during the period July 1713–July 1714 between Johann Ernst's return from Utrecht and the prince's final departure from Weimar. There is some scholarly debate on Johann Ernst's role in the creation of these arrangements, whether he commissioned some from one or both of the musicians or whether Bach, in particular, was studying some of the works collected by the prince for their own sake. There are suggestions that on a visit to Amsterdam in February 1713 the Prince may have heard the blind organist J. J. de Graff, who is known to have played keyboard arrangements of other composers' concertos. In any case, Bach's encounter with the prince's collection, and especially the Italian music it contained, had a profound influence on the development of the composer's musical style.

As well as influencing Bach, Johann Ernst completed at least nineteen instrumental works of his own before his death at age eighteen. These works show the influence of Italian music more than that of German models such as Bach.

Johann Ernst died in Frankfurt after a long illness resulting from a leg infection, possibly a metastatic sarcoma, which, despite the intensive care of his heart-broken mother and medical treatments in Schwalbach, spread to the abdominal area. He was buried, not in Weimar, but in Homburg (Bad Homburg vor der Höhe) in the vault of his mother's family, the Landgraves of Hesse-Homburg. A period of mourning was declared in Weimar from 11 August to 9 November 1715. Music was banned, including in church, resulting in an interruption in Bach's attempt to build an annual cycle of cantatas.

Following his death, six of the prince's concertos were sent to Telemann, who edited and published them in 1718. He himself had already started to have them set before his death. Telemann's own first publication, a 1715 set of six violin sonatas, had been dedicated to Johann Ernst.

According to Walther's Lexicon, published in 1732, Johann Ernst composed 19 instrumental pieces in a period of nine months, shortly before his death, when Walther was teaching him composition. Eight violin concertos are extant in their original instrumentation. Bach transcribed three of these: Op. 1 Nos. 1 and 4 and the Concerto a 8 in G major. Another concerto by Johann Ernst is only known through Bach's transcriptions in C major. No original has been identified for BWV 983: it was possibly transcribed by Bach from a concerto by Johann Ernst. The model for BWV 977 is equally lost: also in this case a possible attribution of the lost original to Johann Ernst is uncertain.

Violin Concerto in B-flat major, Op. 1 No. 1, for violino principale and strings (violin I & II, viola, harpsichord):

Adaptations:

Violin Concerto in A minor, Op. 1 No. 2, for violino principale and strings (violin I & II, viola, harpsichord or cello):

Violin Concerto in E minor, Op. 1 No. 3, for violino principale and strings (violin I & II, viola, harpsichord or cello):

Violin Concerto in D minor, Op. 1 No. 4, for violino principale and strings (violin I & II, viola, harpsichord or cello):

Adaptations:

Violin Concerto in E major, Op. 1 No. 5, for violino principale and strings (violin I & II, viola, harpsichord or cello):

Violin Concerto in G minor, Op. 1 No. 6, for violino principale and strings (violin I & II, viola, harpsichord or cello):

Violin Concerto in G major for violino principale, violin I & II obligato, violin I & II ripieno, viola, cello and harpsichord:

Adaptations:

Violin Concerto in G major for violino principale, violin I & II, viola, bass and continuo, a.k.a. RV Anh. 12:

Instrumentation and key of the model for BWV 984 and 595 are unknown.

Adaptations:

Sonata in D major for trumpet, two violins and continuo (attribution uncertain):

Apart from several performances of the Bach transcriptions, recordings featuring music by Johann Ernst include: