Baroness Orczy 
Sir Percy Leads The Band [PDF ebook] 

Sir Percy leads a band of musicians whose play is of questionable quality. Nonetheless, the disguise enables him to listen in to conversations as revolutionaries lay their plans in an ale house. But his mission on this occasion is to save the La Rodiere family and others from the Guillotine. The band uses the rabble to mask the rescue, as whilst they sing and dance around Chateau Rodiere, it becomes possible to outwit even Citizen Chauvelin, who has arrived on the scene. Treachery from within the band is afoot, however, and Sir Percy has to rely on wit and judgment to bring about an astonishing conclusion.