It's good if you already know some of the music Bowen wrote once he had found his voice, because it allows you to put Bowen's Concerto in it's proper persepctive as one work among his canon, and as an independent work jockeying for position among the other viola compositions written previously and those of the day. On display are all of the influences that eventually amalgamated to become the recognizably mature Bowen style: the harmonic inventiveness of the French school via Debussy, the surging and passion of the Russian romantics via Tchaikovsky, the yearning modality of the new English school and the overwhelming technicolor of the Austro-German school via Strauss in Bowen's orchestration. While it's remarkable that the young Bowen had absorbed all this, it is even more amazing that just a short time later he was able to forge these disparate musics into a style recognizable as York Bowen. (See his Phantasy for viola and piano for the first manifestation of the mature Bowen. York Bowen: Viola Sonatas No. 1 & No. 2; Phantasy for Viola & Piano) The fact that these influences are clearly on display in the Viola Concerto doesn't lessen the incredible impact made by the work. It is just fantastic; compelling, ceaselessly interesting from moment to moment, showing incredible imaginative resources. There is one weak moment: the cadenza in the 3rd movement. It seems to be from another piece, and Lewis Foreman (author of the booklet note) thinks it was actually written by Tertis.
This isn't the first viola concerto, but it is surely the first truly virtuosic viola concertante work. There simply was no viola writing like this up to this time. (Remember that Harold in Italy is really of student level difficulty, and though it came later than Bowen's, Walton's Concerto isn't much more difficult than the Berlioz.) Bowen puts the soloist through paces expected of a violinist, while the orchestra has its own virtuoso duties to fulfill. How is it that violists don't know this work? I can only imagine that Bowen himself didn't try to promote it much, even while Lionel Tertis (the dedicatee) was alive, much less so once he was gone. Trust me, this work is a masterpiece from a young genius, and it should be played everywhere, instead of trotting out tired warhorses like Telemann and Bartok.
From the above you may think that the Forsyth Concerto is completely overshadowed by Bowen's, but that isn't the case. It is a fine work, considerably less adventurous harmonically and stylistically, but a work that is more than professionally written and is completely within the bounds of English taste at that time. Forsyth's is a classy work which wears its virtuosity lightly. It too could easily replace some of the hoary viola concertante works to which we're usually subjected.
All in all, a great, important disc, and in the case of the Bowen, a find and a revelation in the development of the virtuoso viola repertoire. Get it!.