What on earth would composers do without Ah! Vous dirai-je, Maman or Twinkle Twinkle Little Star as the heathens amongst us would have it? This piece follows the standard format of atmospheric introduction, simple theme and variations of increasing difficulty but it's great! The theme is passed around all four players so everyone has a chance to shine, whether it's to show off finger technique, fast tonguing or a beautiful sound. Dancla died in 1907 so the style here is Romantic. He didn't much venture out of G major though so it might be wise to cut a variation or two in performance. It's also a piece which is extremely difficult to take seriously!
Difficulty level, roughly compared to ABRSM exam grades. 0 is beginner, 9 is advanced (beyond grade 8).