Despite his name, he was an Italian composer. He was born to an Austrian military man, Colonel Wilhelm Kapsberger, who lived in Venice. During his career, the composer often Italianized his Christian names to Giovanni Girolamo Kapsberger.
He quickly became famous as a virtuoso lutenist, which gave him entry to the leading clerical and aristocratic families, where he was treated as an equal as a "German nobleman." His skill and fame as a player also prompted his circulation in artistic and literary circles and his success as a composer flowed from the networking that resulted from this. He was a member of some of the "Academies" (more or less regular discussion and performance groups) that were important in artistic life of the time. These included the Accademia degli Umoristi and the Accademia degl'Imperfetti.
He had close contacts with the orders of St. Stephen and St. John and his publishers were members of these groups. In like manner, he was a friend of the poets Francesco Porta, Giulio Rospigliosi, and Giovanni Ciampoli, as well as painters and scholars. He wrote some of the most innovative and outstanding lute music of the time and was noted for a virtuoso style with well-chosen ornamentations and wrote attractive, lively dance music, as well as songs. He wrote a Sinfonie a quattro with orchestra and a solo group of violin, cornet, lute, chittarone, harp, and harpsichord, contrasting their solo sonorities against each other and the orchestral group most inventively.
In 1622, he was chosen to provide a major vocal work, Apotheosis seu consecratio, as part of the ceremonies celebrating the canonization of St. Ignatius Loyola. Kapsberger firmed up his relationship with the church hierarchy by writing a set of vocal compositions on poems of Pope Urban VIII and other music dedicated to members of the Pope's family, the Barberini. He composed a Missae urbanae in 1631, reportedly in an effort to introduce his music into the playbook of the Sistine Chapel's chorus.
Kapsberger's last publication was in 1640 and nothing is known about the rest of his life. His vocal music is highly uneven in quality. He wrote two sets of Cantiones sacrae, which are regarded as his best work for voices. Also highly regarded is his first book of villanellas (1610). Otherwise, he had a tendency to resort to standardized vocal ornamentations or roulades to such an excessive degree that the music is boring, as well as clumsy handling of texts and lack of formal balance of phrase lengths. His only dramatic works (the representative drama written for the Loyala canonization and an opera, Fetont) are lost.