The stage of the Royal Albert Hall has a rather unfortunate habit of making orchestras seem incidental. Stretching endlessly across, one of the world’s largest organs by way of backdrop, even the most generous conventional ensembles take on Lilliputian proportions. Youth orchestras, with their Romantic scale and do-or-die attack, often emerge best from this encounter, as the Simón Bolívar and Gustav Mahler ensembles have recently proved. Framed by eight double basses and five horns, the Royal Albert Hall finally starts to make sense as a performance space. In the hands (and lips) of the Australian Youth Orchestra last night, it not only made sense, it made music.