This edition containing Italian (Roman) Organ music is the result of studies done at the Vatican Library in Autumn, 1977. Among the numerous manuscripts found in Fondo Chigiano, there are several sets of manuscripts which consist of Organ and Harpsichord music written between the years 1630 and 1640. These manuscripts are listed in G. Baronci's hand-written catalogue (1929) as Chigi Q IV 24-29. The manuscripts of Q IV 25 contain exclusively works by Frescobaldi: a partita, eight toccatas, three canzonas and two capriccios, along with a recercare (sic.) and an incomplete Recercare Cromatico, which is included as no.2 in the present publication. These pieces by Frescobaldi could have been published previously by A. Santani in XIV Composizione inedite di Frescobaldi (Rome, 1940); they are not, however, included in Pidoux's Gesamtausgabe (published by Barenreiter Verlag). Bengt Johnsson has been daring enough to complete this ricercare, which is even more advanced than the ricercare from Fiore Musicali (1635); Ricercare Chromaticho post il Credo (Barenreiter edition vl. V, p. 34).