Structure
The concerto follows the classical three-movement pattern of fast-slow-fast. As such, musicologist Kenneth Gloag points out, it fits in a pattern on Tippett's concerto output that mirrors a historical trajectory—from that of the concerto grosso in his Concerto for Double String Orchestra to that of hybrid concerto grosso and instrumental concerto as typified by his Triple Concerto, Beethoven's Triple Concerto and Johannes Brahms's Double Concerto.[3]
1. Allegro non-troppo. Conventional in its sonata form, this movement opens gently, reminiscent of the Beethoven Fourth Concerto, before the full orchestra enters in an A-flat passage that emphasizes the pastoral tone of the music. Woodwind arabesques introduce a small instrumental ensemble of muted viola, muted horns and celesta. Tippett had used a similar ensemble in The Midsummer Marriage, as Ian Kemp explains, "to emphasize the timeless presences that move beyond the surface realities of life ... mysterious yet familiar."[4] The soloist interrupts this group by introducing a group of themes and motifs labelled "second subject." This visionary tone returns twice—at the climax of the development section, and during the solo cadenza. These episodes, Kemp says, serve as "unpredictable but reassuring reminders that the vision [of those "timeless presences"] can never be lost."[4] Like in The Midsummer Marriage, Tippett juxtaposes passages of contrasting tone and musical material. One stance of this, as John Palmer points out on Allmusic.com, is the transition to the second theme. There, "an energetic line of sextuplets begins a canonic process that becomes the accompaniment for a lyrical melody of sustained notes and arpeggios in the solo viola. The sextuplets disappear, horns accompany, and the celesta enters quietly with the rhythm of the viola melody. Without warning, winds and brass loudly state fragments of irregular length from the sextuplet passage between rests, bringing the forward motion to a halt."[5]
2. Molto lento e tranquile. Compared with the serenity of the opening movement, the central one is what Kemp calls "dense and disturbing, a kind of tournament between faceless close canons from pairs of wind instruments and manic cascades from the piano."[4] These exchanges continue on their separate courses until the high strings enter. The soloist, now more ruminative, calms the proceedings.[4] British musicologist and writer Arnold Whittall considers this movement "more radical and forward-looking" than the opening one, "its textural and tonal conflicts embodied in a polyphony which is elaborate even by Tippett's standards, and with a tripartite form which is progressive rather than symmetrically closed"—a-b-c instead of the usual a-b-a.[6]
3. Vivace. While the opening Allegro might have evoked the Beethoven Fourth Concerto, the finale is more akin to the same composer's "Emperor" concerto, implied from the opening key change from B to E-flat and the high spirits of the music on the whole. A long section for orchestra alone (a contrast to the near-continuous solo piano in the previous movement) unrolls in three parts which contain a number of small motifs, a striding, bluesy theme at its central section and the reappearance of the celesta in a codetta. The soloist enters with his own dramatic theme. This sequence of events is actually "the first episode in a scheme in which the orchestral section is the rondo theme, now divided into its three parts with episodes between" (Kemp).[4] The second episode combines piano and orchestra, the third is for piano alone and the last a duet for piano and celesta. The opening rondo returns and a short, jubilant coda ends the concerto in C major.[4]
Resemblance to The Midsummer Marriage
Tippett himself noted the piano concerto's close resemblance to his opera The Midsummer Marriage and called its music "rich, linear, lyrical, as in that opera."[7] According to Wilfrid Mellers, Tippett's following a major choral work or opera with an important orchestral or instrumental one was a pattern Tippett followed more than once. Among the composer's other works, he wrote his First Symphony after completing his oratorio A Child of Our Time and his Second Piano Sonata after his opera King Priam.[8] Kemp and Gloag cite the concerto's expansive orchestral lines and florid decoration of these lines as being highly reminiscent of the opera The Midsummer Marriage. They cite particularly the composer's use of celesta "to light up a realm of mystery and magic" (Kemp).[4][9]
The opera also influenced Tippett's approach to the solo writing in the concerto. While not entirely ignoring the traditional aspects of concerto writing, Tippett focused primarily on a shimmering quality in which, Kemp writes, "the harmonies emerged from the pedalling [sic] of lines of unequal groups of short notes."[4] The composer had used this approach in his song cycle The Heart's Assurance, written in 1951, especially in his setting to the words "the meadows of her breath in the third song (the music for which, Kemp suggests, "sounds as if it was the direct link to the opening phrases of the concerto").[4]
Influence of Beethoven
Gloag points out Beethoven's Fourth Piano Concerto as an influence in the Tippett concerto.[10] The composer himself described the Gieseking rehearsal of the Beethoven as "the precise moment of conception" for his own work.[7] Gloag suggests the quiet opening of the concerto, with the soloist introducing a G major harmony, as the most obvious fingerprint, from a compositional standpoint, to the Beethoven Fourth.[10] The return of this opening gesture in the key of A-flat major, Gloag continues, "reflects Tippett's engagement" with Beethoven's Piano Sonata No. 31, Op. 110.[11] However, according to Arnold Whittall, Tippett "turns the conventions of Beethovenian sonata form inside out" in the opening movement. As opposed to the dynamic intensity present in Beethoven works such as the Fifth Symphony and the "Emperor" Concerto, Tippett allows "change to take place gradually: ambiguity and avoidance of the explicit are exploited for their capacity to arouse expectations of coherent continuation."[12]