RV555 poses a riddle—the identity of the pair of instruments that appear for the first time in the finale and are labelled ‘2 Trombe’. The problem with accepting this designation at face value is that these parts, while often fanfare-like in character and therefore related in a general sense to the trumpet style, contain too many notes in the octave above middle C that are unplayable on the natural instrument. There are other technical difficulties, and also problems of balance with the rest of the ensemble. Robert King’s novel solution, which I find fully convincing, is to interpret trombe as a shorthand form of violini in tromba marina (the recording employs ordinary violins played near the bridge and making maximum use of harmonics in an attempt to simulate the historical instruments). There is a precedent for this. For a similar concerto in C major, RV558 (specially written for a visit of Frederick Augustus’ son to the Pietà in 1740), Vivaldi’s copyist wrote ‘violini in tromba marina’ on the title-page but abbreviated this to ‘trombe’ or ‘trombe marine’ in the score itself. The relevant parts in RV555 possess exactly the same general characteristics as those in RV558. Similarly, the ‘violino in tromba’ required in the solo concertos RV221, 311 and 313 may in reality be, as argued by Cesare Fertonani in a recent book on Vivaldi’s instrumental music, a ‘violino in tromba marina’. The point is that, with Vivaldi, so many options remain open: what was yesterday’s heresy can so easily turn into today’s orthodoxy.
from notes by Michael Talbot © 1998