The connection between Wales and the harp is a long-standing one, and Mathias's part in it began 12 years before his Harp Concerto was written, with Improvisations for harp solo; even a Welshman has to learn how to cope with such an idiosyncratic instrument. He learned his lessons well—even using semitone pedal glissandos in the second movement, and he keeps the harp audible by alternating its solo passages with orchestral ones or, when the two are working together treating the orchestra with a light touch (the celesta is used as a particularly effective companion to the harp), at other times resorting to the more familiar across-the-strings sweep. Two movements have declared Welsh associations: the first juxtaposes but does not develop three themes the second is a 'bardic' elegy; the last is simply ''joyful and rhythmic''. The whole makes pleasing listening appealing to the emotions and imagination rather than the intellect.
Mizushima is a soldier in the Japanese army in Burma in World War II. He's a good soldier and frequently plays his harp to entertain his fellow soldiers. When the war comes to an end, he is asked by the British to go into the mountains to try and convince a Japanese troop to surrender. Given only 30 minutes to convince them, Mizushima is unsuccessful - they would rather die with honor - and the British attack. Deeply affected by what has happened, he becomes a Buddhist monk, traveling the countryside burying the remains of Japanese soldiers. He is unable however to rejoin his brothers-in-arms.