J.S.Bach is one of the most popular composers in the world today, and his famous pieces are performed on the harpsichord, the most popular keyboard instrument in the West at the time.
For those who are not familiar with the harpsichord, there is an explanation of the instrument and how it differs from the piano.

J.S.Bach (born 21 March 1685 in Eisenach - died 28 July 1750 in Leipzig)
Johann Sebastian Bach was the youngest of eight siblings in the Bach family, a musical dynasty that spanned over 200 years and produced numerous musicians.
A follower of Lutheranism, Bach never left Germany and served the German king and church as a court musician for the rest of his life.
He was a prolific composer, writing in a wide range of genres, and is said to have composed over 1,000 pieces before his death in 1750 at the age of 65.
His works are now usually numbered BWV (Bach-Werke-Verzeichnis), but this was not done by Bach himself.
The numbering system was proposed by Wolfgang Schmieder in his catalogue of J.S. Bach's works, which he compiled in 1950.
While other composers' works are often numbered in the order of composition or publication, the BWV is numbered according to genre. The works for harpsichord solo are grouped together in BWV 772-994, for keyboard instruments other than the organ.
During his lifetime he was well known as a performer, but less so as a composer, and after his death his works were performed less and less due to changing times and trends.
It was not until 1829 that Bach's works came back into the limelight. In 1829, Mendelssohn performed Bach's Matthew Passion, and many of his works came to be enjoyed.
Bach's music continued to influence many of the great masters of classical music, including Mozart, Beethoven and Chopin, and he was later dubbed the "Father of Music".

Invention
Bach composed his Inventions and Sinfonias for the musical studies of his son Wilhelm Friedemann.
It is an instrumental piece in the imitative style, consisting of a short presentation and a longer development, which in some cases closes with a short recapitulation. Unlike the fugues and sinfonias, there is no use of the key of genus in the response to the theme.
The autograph copy of the score has the following title
I would like to appeal to all lovers of the clavier, and especially to those who wish to learn it, to (1) not only play the two voices beautifully, but also, if they improve further, (2) handle the three obbligato voices correctly and skilfully, and at the same time not only obtain the invenzio, but also develop it skilfully, and (3) play the cantabile. In particular, it provides clear instructions on how to master the cantabile technique and, at the same time, to develop a strong interest in composition. Johann Sebastian Bach, Court Musician of the Margrave of Anhalt-Köthen, completed this work in 1723.
The whole cycle is arranged in a scale from C major (the first piece) to B minor (the fifteenth piece).

Well-temered Clavier
Average tuning is a method of dividing a note into twelve evenly distributed tones, from one note to one octave higher.
Modern pianos are usually tuned in average tuning.
The first two volumes (1722) and the second volume (1744) were composed during the period when he was working for Köthen and teaching his eldest son Friedemann music.
Both volumes 1 and 2 consist of 24 preludes and fugues in the major and minor keys, each with 12 principal notes.

French Suite
Composed around 1722, this suite for keyboard consists of dances based on armand, courante, sarabande and gigue. There are six pieces in all, the first three in minor and the last three in major, so that the suite is harmonically unified. Although Bach did not travel to France during his life, he was able to study many scores and to make the style of French harpsichord suites his own, since the distribution of scores was already established in Europe at that time.
Bach himself did not name it the French Suite, but it was later called the French Suite because it included the dances that made up the French style.
No. 5, which we will perform, consists of Armand, Courant, Sarabande, Gavotte, Boulez, Rule and Gigue.

Chromatic Fantasia and Fugue
As the title suggests, a chromatic fantasy followed by a recitative and a fugue based on a chromatic theme. There are a number of transcriptions, the oldest of which is by J.T.Kreps, a pupil of Bach in Weimar, so it was probably composed in Weimar (~1717) or Köthen (1717~1723).
A fantasy is a title given to a piece of music that is written freely and without formal restraint. In the score there are only chords, and the performer is free to play arpeggios on his own account.
The second half of the piece is a recitative of sorts.
In the fugue, a chromatic scale is used in the first half of the theme. The first four notes of the theme are rewritten in German as A, B, H, and C. If you replace these notes, you get BACH. If we replace them, we get BACH. In other words, Bach has his own name at the beginning.
Bach often used the number 14 (BACH) or 41 (J.S.BACH) as the number of notes in the theme of the fugue or the number of songs in the collection, in accordance with the field of numismatics, in which his name is replaced by notes and each letter of the alphabet has a numerical meaning.

Italian concerto
Bach was extremely keen to learn instrumental concertos with an Italian character when he was a relatively young man (after 1708) at the court of Weimar, where he held the position of court musician, court organist and concertmaster.
The solo concerto is a form that originated in 17th-century Italy as a violin concerto, developed from the concerto grosso form.
In order to make the contrast between the tutti and the solo part clear, Bach used the symbols for forte and piano. To make this clear, Bach also gives the work a title: 'For Clavizimbel with two-hand keyboard'. By giving it this title, he consciously excluded the possibility of it being played on the clavichord, which he preferred.
In the slow movement, where the idea of the Italian concerto is particularly evident, the right hand functions exclusively as a concerted solo voice, while the left hand has the task of accompaniment throughout.

Toccata
A toccata is an improvisational piece with fast passages and small changes in tone, mainly played by keyboard instruments, and is characterized by technical expression. toccata comes from the Italian verb toccare (to touch), which means to try out an organ or harpsichord in order to see its tone or tuning. Bach's toccata was written in the 17th century.
Bach's Toccata are seven works for harpsichord or organ, composed between 1705 and 1714.
Each of them opens with a toccata, which is followed by a series of musical ideas, each with its own character.
The Toccata in E minor, which we will be performing, consists of an introduction, fugue 1, adagio and fugue 2. The opening section does not have the typical running lines of a toccata, and begins in a more subdued way than in other works.
The first fugue is a double fugue in which the two themes are presented simultaneously.
The last fugue is a genuine work, but an old manuscript in the Neapolitan Conservatory contains a fugue with a similar theme, which Bach seems to have borrowed.

Translated with www.DeepL.com/Translator (free version)