BBC National Orchestra of Wales, St David's Hall, Cardiff

Harps and daffodil trumpets

Projected red dragons and daffodil trumpets lit up the back of the stage. Leeks and daffodils adorned buttonholes. No one could accuse this St David's Day concert of forgetting its identity. With Prince Charles in the audience and two works – one a world premiere – by Welsh composers forming the backbone of the programme, the sense of national pride was palpable.

Karl Jenkins's Over the Stone, a six-movement double harp concerto with strings and percussion, was written for Catrin Finch and her teacher, Elinor Bennett. The 21-year-old Finch has held the title of Harpist to HRH The Prince of Wales since his revival of the ancient tradition in May 2000, and this work is the first commission to arise from her Royal appointment.

The jocund opening "Carillon" and the waggish "Songs of the Bards" entertained with snappy rhythms and sharply shifting Celtic harmonies. A few notes stretched a long way in the mesmeric "Eternal Dream", but Over the Stone was an atmospheric set of improvisations for harps over the strings' 18th-century Welsh folk melody. A virtuosic, extended cadenza for both soloists, with a brief reference to the Welsh national anthem, led directly into the "Vamp Latino" finale, whose infectious style evidently delighted the soloists.

Easy on the ear but brief in the memory, Over the Stone is an agreeable addition to a scanty genre. As a vehicle for two talented harpists, it was suitably showy. The percussion enhanced the soloists' colours, but the strings merited more challenging accompanying material.

A rare chance to hear the Third Symphony by South Walian William Mathias crowned the evening. The composer wrote it near the end of his life, while recovering from a major operation, a circumstance that accounts for the work's gripping mix of disquieting intensity and fervent, life-affirming spirit.

This was clearly a labour of love for conductor Grant Llewellyn – he gave the world premiere of the symphony in 1991 in St David's Hall with the BBC National Orchestra of Wales, and they recorded it the following year. Their interpretation a decade later was compelling. The opening movement's rhythmic energy was sustained by alert and committed playing from all departments. The central Lento Appassionato's lyrical, haunting main theme, first heard on cor anglais emerging from Celtic mists, remained in the mind long afterwards. An exotic motif in the Finale became terrifyingly obsessive in the closing bars, before a tumultuous final crescendo carried all before it.