Birmingham Royal Ballet’s latest mixed bill is a testament to director David Bintley’s taste for the challenging. Among the evening’s ambitious undertakings are a balletic interpretation of a physics formula, a meditation on the figurative death of ballet, and a didactic tale about environmental damage and its effect on endangered species. The troupe’s performance occasionally wavers on the quality front, but what it lacks in consistency it duly makes up for in gusto and tenacity.

The bill opens with an ode to Einstein’s famed mass-energy equivalence formula, E=mc2. Each component of the equation (energy, mass, celeritas) is granted its own movement, the three connected by a brief interlude entitled ‘Manhattan Project’ (a nod to the infamous venture that exploited Einstein’s findings to create the first atomic bomb).

A lively spark informs the terpsichore in ‘Energy’, but the choreography ultimately proves too prim to fully channel the electric nuances of the punchy score and underlying theme. ‘Mass’, on the other hand, is hypnotic, a true master class on the art of partnering. The movement showcases pliant extensions and masterful lifts, exploring notions of gravity and tempo through a series of experimental pas de deux and trois. An eerie solo channeling the gravitas of the 1945 Hiroshima bombing bridges the gap before ‘Celeritas2’, a playful take on the speed of light portion of the equation. This segment, peppered with jaunty sissones and grand jetés, sees dancers prance and gambol to a charmed medley of bells and cymbals, twinkling like Christmas lights come to life.

Tombeaux is a stark contrast to the preceding piece in both mood and message. Billed as “a lament to the end of British ballet,” the piece is not as funereal as its subject suggests; still, the tone is reflective rather than forward-looking, its resonance quiet and oblique. Bintley opts for a passive approach over a fervent one, adorning the work with controlled pirouettes and a generous smattering of gentle cabrioles and soutenus. The overall effect registers as restrained and a little bland at times, though the myriad penchés and développés on display go a long way in highlighting the cast’s strength and flexibility. Were they tighter as a group, Tombeaux might pack a little more punch.

The momentary lull is quickly rectified with the onset of ‘A Still Life’ at the Penguin Café, which ushers in a buoyant pace and delightfully jubilant humour. Kicking off the proceedings is a waltzing penguin, followed closely by a bevy of merry animals, among them a sashaying ram, a jigging kangaroo rat, a Morris-dancing flea, and shimmying zebra. Each character is given its own vignette, and alongside the joyful score and mischievous tone is a undercurrent of morality: all of the species represented are endangered, and human indifference is a major contributing factor. This is illustrated most clearly in the zebra’s sketch, which sees a pack of haughty fur -clad women strut by, too engrossed in their own frippery to acknowledge his plight.

The admonitory motif persist right through the raucous coda, which sees the animals board an ark two by two and gaze into an uncertain future. Overt perhaps, but the reconciliation of frivolity and solemnity is powerful nevertheless.