The surviving keyboard music is cast in the typical southern German style, combining strict German counterpoint with Italian styles and techniques; Frescobaldi and especially Froberger were the most important influences. Most of Kerll's keyboard works are playable on both pipe organ and harpsichord, the exceptions are four dance suites composed for harpsichord and two organ toccatas: "Toccata quarta Cromatica con Durezze e Ligature" and "Toccata sesta per il pedali". Partial chronology can be established using Kerll's (incomplete) catalogue of his own works which is included in the 1686 "Modulatio organica" (it is the earliest surviving thematic catalogue of a specific composer's works): it lists 22 pieces, 18 of which were composed by 1676 at the latest. The earliest known composition by Kerll, "Ricercata à 4 in A" (also known as "Ricercata in Cylindrum phonotacticum transferanda"), was published in 1650 in Rome.