"Toccata, Adagio and Fugue in C, BWV 564" is one of Johann Sebastian Bach's most famous organ works. 1 Toccata: This part starts with an introduction that sounds like improvisation. It has fast, single-note passages like a concerto's cadenza. At measure 32, it changes to a bright, full sound like an orchestra. 2 Adagio: This part is slow and very beautiful, with a sad feeling in a minor key. 3 Fugue: In 6/8 time, this part is lively and bright, like a dance such as a Gigue or Passepied, even though it is not labeled as a dance. In my previous publication, "Toccata & Fugue, BWV 565 for Violin and Viola," I showcased the unique beauty of string instruments. Similarly, in this piece, the beautiful melody of the Adagio fits perfectly with the Violin and Viola, as if it were originally composed for them. The dance-like energy of the Fugue is also easier to express with string instruments. When two people perform this piece, it creates an interesting dialogue, almost like a conversation. The introduction of the Toccata reflects this, inspired by my students who would chat enthusiastically before starting their practice. Their conversation in the music lasts for 31 measures without any chords together. The short unison phrase in measure 13 symbolizes their agreement to start playing together. After that, their conversation continues, with triplets and important motifs of this movement appearing, increasing the expectation for the ensemble to begin. From measure 32, the real ensemble playing begins. Although we don't know what Bach imagined when he wrote this introduction, I now hear it as a conversation, even when listening to the original organ version. In the Adagio viola part, the continuo notes are marked in black, and the notes that create harmony are marked in blue. Players who can control the volume balance of double stops should balance it so that the continuo flows naturally. Players who are not skilled in playing double stops, it might be better to omit the blue notes in difficult sections. If omitted, the section might feel empty, but with careful playing before and after, it could still sound natural.