Performances of oratorios, masses, and cantatas by Bach, Handel, Mozart, Mendelssohn, Britten, and Rossini are the choir's main focus.

Additionally, the boys' choir has participated in the Lucerne Festival as well as the following opera performances in Basel: Die Zauberflöte, Tosca, Mefistofele, Carmen, La Bohème, Carmina Burana und Macbeth.

Ulbrich turned to Ernst Lipp, a fellow singer in the Bach Choir and president of the Kommission für den Unterricht in der Biblischen Geschichte ("Commission for the Teaching of Biblical History", KUBG), and suggested that he found a singing school for the preservation of choral tradition that was in the service of the church, but independent of the YMCA.

Nevertheless, the KUBG approved the charter, which Ulbrich had previously written together with Lipp and YMCA youth secretary Jakob Staehelin, and he took responsibility for the still-to-be-founded choir.

The first rehearsal took place on August 19, 1927 in the Bishop's residence of the Basel Münster; soon, though, they moved due to the heating problems in the Katharine Chapel of the cloister.

The first public appearance occurred on October 30, 1927, as a part of a church service in the Martinskirche, but it was such a fiasco (the 19 boys who did show up sang very poorly) that Ulbrich threatened to resign.

Their third appearance, a Bach concert in April 1928, was also their last before a long summer break, during which a large advertising campaign was carried out to ensure the continued existence of the group.

In August, 1929, the Chorschüler der evangelisch-reformierten Kirche Basel-Stadt ("Choir students of the Protestant Church of Basel-City"), which consisted of former choirboys whose voices had changed, was founded.

Nevertheless, the choir students appeared at Hamm's Free Organ Recital in December, 1928, but the group was ultimately unable to survive (for the time being).

On December 22, 1929, the boys' choir organized their first full concert: a Christmas liturgy at the Münster with the locally renowned soprano Helene Sandreuter, which was a big success.

Meanwhile, the choir had grown to 88 boys, which necessitated changing the rehearsal space from St. John's Chapel to a larger and considerably more expensive location in Nadelberg by the Peterskirche.

Since Ulbrich had to serve in the military until July, 1940, Emil Herrmann and Helene Sandreuter were entrusted with the interim direction of the choir, leading to temporary cessation of voice lessons.

In February, 1970, Hermann Ulbrich and Helene Sandreuter announced their resignations from their positions with the choir effective at the end of June.

Markus Ulbrich placed a heavy emphasis on the works of Heinrich Schütz, with performances of The Seven Words of Jesus Christ on the Cross (1791), St. John Passion (1972), and History of the Resurrection (1974).

In the summer of 1973, their first concert tour took place in the Bernese Oberland and their first record, a collection of choral and organ works by Felix Mendelssohn, was made.

In 1974, the Gregorian Chant Circle was founded, which fosters continued training in church music, both for older current choir members as well as alumni.

In the end, the choice was between German cantor Klaus Knall and the leader of the Muttenz youth music school, Beat Raaflaub.

In September, 1986, soloists from the KKB participated in a production of The Magic Flute for the first time at the Theater Basel, and later in Bern and in Freiburg im Breisgau.

At the beginning of October, the choir was able to make a scheduled trip to sing in Saint Petersburg, although only weeks before, Mikhail Gorbachev had attempted to stop it.

In response, it was agreed at the yearly general meeting that a financial reservoir needed to be developed that could weather a bad economy, namely a concert tour endowment.

In May, the first European Festival of Youth Choirs took place; the KKB, with Winkler as its business manager and Raaflaub as its musical director, was heavily involved with the planning and execution of the event.

In 1999, there followed a concert tour through the Czech Republic with appearances in Brno, Hradec Králové, Pardubice, and Prague, as well as performances of Bach's Christmas Oratorio in December.

In September, the choirboys participated in a performance of Mahler's Third Symphony during a Swiss concert series; other engagements at the Lucerne Festival followed in subsequent years.

In December, 2002, the KKB performed Handel's Coronation Anthems and the Chichester Psalms, choreographed by Parwin Hadinia in the Theater Basel, for its 75th birthday.

Jürg Rauschenbach, who was intimately involved in the execution and the success of the large concert tours through South Africa and Brasil, stepped down as president in 2002.

In 2003, the KKB took part in the first Venezia in Musica international choir festival in Venice and Jesolo and Performed Bach's Johannes Passion for Easter, 2004.

Three years of fall concert tours of Germany took the KKB through Calw, Limburg, Göttingen and Rotterdam (Netherlands) in 2004, Nederhof, Wiesbaden, Wirges and Luxembourg in 2006, and Frankfurt (Oder), Saalfeld, Jena, and Sondershausen in 2007.

During the months immediately following Raaflaub's resignation, assistant director Herter took partial responsibility for leading the choir, while Teutschbein stayed in Germany.

Teutschbein has been the KKB's musical director from February 2007 until Autumn 2016, and his first joint project with the choir was to organize the sixth EJCF in May 2007, in Basel.

In 2014 the Knabenkantorei Basel performed the late version of Johann Sebastian Bach's St. Mark Passion reconstructed by Alexander Grychtolik.