Andrew Bird is a world-class whistler. He’s also a concert-level violinist.
But neither of those are likely to be your first impression of his breakout album, Armchair Apocrypha.
Your first impression is much more likely to be that he is a master crafter of mellow pop. His whistling isn’t used as a novelty, and his violin isn’t made a focal point too often.
Rather, both are used as pieces of the larger composition, which also includes his masterfully played guitar, restrained drum sets (that let loose when they need to), Broadway-dramatic pianos, the occasional drum machine and synthesizer, and Bird’s own voice (of which he also has mastery).
Andrew Bird has admitted that he finds most pop music and indie rock “repetitive and boring,” which is interesting considering that he makes pop music in the subgenre of indie rock. But the discerning listener will hear his love of classical and jazz poke through the tracks. From the pizzicato  strings that are generously seasoned throughout the record, to the laid back shuffle of opener “Fiery Crash,” Bird’s love of music outside of pop tradition makes his personal brand of pop music a sure standout in the plethora of “indie” acts that press their albums to vinyl, play on Austin City Limits, and have articles written about them on Pitchfork.
It also gives him a discerning ear to pair with his seemingly endless talent, ensuring that his music is not only masterfully played, but tastefully composed, and we, the listeners, are the benefactors.