A new app from Touch Press is always cause for celebration. This one combines an illuminating text, insightful video commentary, and two acclaimed performances in an examination of the life of Antonio Lucio Vivaldi and his most famous work.

Suzy Klein introduces 'Vivaldi's Four Seasons' (Touch Press/Grammophon)

In Vivaldi’s Four Seasons (iOS, $10.99; Gr 9 Up), Touch Press, with the help of Deutsche Grammophon, has engineered a production that mirrors the groundbreaking work this developer accomplished in Beethoven’s 9th and the Liszt Sonata in B Minor. On opening the app, viewers have the option of beginning with a brief history of Antonio Lucio Vivaldi’s life and composition or one of the two complete performances of the Four Seasons:  the celebrated interpretation by Trevor Pinnock or Max Richter’s Recomposition, an “unmistakable homage to the original.” The history covers the composer, violinist, and cleric’s life from his birth in Venice in 1678 to his death in 1741, his career highlights, and the “genius and modernity” of his work. Each of the violin concertos in the Four Seasons (“Spring,” “Summer,” “Autumn,” and “Winter”) is examined in detail through bar-by-bar descriptions of the music and information on the four sonnets originally printed with them. Interspersed is video commentary by cultural critics and musicians (Suzy Klein, Daniel Hope, and Avi Avital), who discuss the works in general terms and consider the technical aspects of the compositions. Topics addressed include the rediscovery of Vivaldi in the 20th century; the composer’s “operatic mind”; his use of the violin; and the two recordings offered here, with audio selections. Sound quality is excellent throughout. A BeatMap consisting of dots representing the various instruments of the orchestra is visible as users listen to either of the performances. (Pulsating dots indicate when their corresponding instruments are playing.) Bars stretching across the bottom of the screen keep time and note the measure, while a tap to a treble clef symbol will bring up sheet music for individual instruments. The Pinnock performance adds a third bar to the screen, presenting a choice between “sonnet” and music “commentary.” For example, just moments into “Winter,” the “sonnet” view reads: “In the strong blasts of a terrible wind….” Under commentary, this note appears: “A virtuosic ‘harsh blast’ of wind from the violin primo…." The Richter performance provides three simultaneous views of the musicians and a Beatmap, any of which can be enlarged to full screen. (Holding a finger on the map will solo each section.) While this is a deep and complex production, both fans of classical music and those interested in learning more about Vivaldi and/or music will find much to enjoy in this splendid app. Schools with music programs, libraries with music collections, and any collection experimenting with circulating iPads should consider it an essential purchase.--Mark Richardson, Cedar Mill Community Library, Portland, OR