Jake Heggie is the kind of composer that musical theatre - and I make no distinction between musicals and opera or indeed any other innately theatrical form - needs to embrace. It's not surprising that operas like Dead Man Walking or most recently Moby-Dick have found success and a distinctly broader audience on the other side of the Atlantic - because Heggie instinctively "gets" the music of words and through melody (that still much maligned enchantress) carries the emotional memory of a moment, a connection, a feeling, forward. At a time when contemporary opera (particularly in Europe) is still predominantly the domain of the contemporary music network, the likes of Heggie remind us that opera is as much about songfulness (as in arias) as arias or songs are about the essence of drama, albeit on a smaller scale.

I can do scant justice to this collection in the space permitted but suffice it to say that these songs "sing" most ardently. Heggie is not afraid to acknowledge, indeed embrace, America's Broadway heritage in the way his tunes "hook" us - be it an isolated phrase or a longer line - but he displays at all times a really composerly instinct in the way these songs are structured. The two sets of duets, for instance: Facing Forward/Looking Back and Here and Gone. The former examines that most special relationship of mother and child, or to be more precise mother and daughter, through the harmonic tensions and equivocations of two-part counterpoint where consonance is always a whisker away from dissonance or in one instance - the Armistaud Maupin setting "Mother in the mirror" - downright abbraviseness. One of these settings, "Let it go", is of Heggie's own words - an imagined conversation with his father who committed suicide when Heggie was 10. You don't actually need to know that information in order for the aching truth of the duet to to take hold but it does help to explain how and why the melodic interaction is so special. Frederica von Stade and Joyce DiDonato do it proud.

Paul Groves and Keith Phares do likewise for Here and Gone, poems by AE Housman and Vachel Lindsay which give resonance to the concept of love unrequited only to be acknowledged after it is too late. Every word here finds an apposite musical response, be it the stupendously bitter "Factory Window Song" (so redonlent of Owen's "We walked quite friendly up to Death" from Britten's War Requiem) or the heart-breaking resignation of "The half-moon westers low".

Heggie's setting of Rilke's "To say before going to sleep" is glorious and solitary, beautifully realised by Joyce DiDonato, who also brings an opera singer's empathy to Heggie's musical reimagining of the final monologue from Terrence McNallay's play about Maria Callas, Master Class. How completely Heggie relates to the poignant subtext of this "confessional". The isolation and unforgiving "hollowness" of the line "Besides, it's all there in the recordings" says more about Callas's losses - her one true love and career - than the entire play.