Sous le Dôme épais (under the dense (leafy) canopy) is an aria from the opera Lakmé by Léo Delibes in an arrangement for three guitars by Andrew Forrest. The piece is known world-wide as Flower Duet. The arrangement is an abbreviated version, but that’s not bad because the original repeats the melody three times.
The arrangement is not particularly easy, all parts need practice. The result, however, is a nice piece of music that many people will recognize, although some will connect the tune to commercials!