Charles Ives, c1948. Source here.

Charles Ives (1874–1954) achieved considerable fame as the author of Life insurance with relation to inheritance tax (1918). But That’s Not Important Right Now. His music (mostly written before 1927) took much longer to be appreciated.

His style, At a Time When it was Neither Profitable Nor Popular, offers a most distinctive American take on playing out the clash of cultures, in a random montage of dissonant soundscapes—hymn tunes, town bands, and so on. See e.g. the ever-perceptive comments of Alex Ross (The rest is noise, pp.140–46, in a chapter aptly titled “Invisible men”) and Richard Taruskin (The danger of music, pp.51–9, 186–90).

Mahler, then being fêted in New York, admired Ives’s music—indeed, they shared a taste for incorporating popular soundscapes. Later, insiders like Henry Cowell, Elliott Carter, Aaron Copland, John Kirkpatrick, Nicolas Slonimsky, Lou Harrison, and Bernard Herrmann began to promote his work, before it was popularised by Leonard Bernstein in the 1950s. John Cage, with his affinity for the random, was another fan:

I doubt whether we can find a higher goal, namely that art and our involvement in it will somehow introduce us to the very life that we are living, and that we will be able, without scores, without performers and so forth, simply to sit still to listen to the sounds which surround us and hear them as music.

By the 1960s The unanswered question (1908) was a popular concert item:

How impressive to recall that my enterprising teachers at the time expanded our horizons by choosing this for my school orchestra, in a concert that also included Ravel’s Ma mère l’Oye!

Edouardo Paolozzi, Central Park in the dark some forty years ago,
from Calcium light night series (1974­–7).

Here’s Central park in the dark (1906, original title A contemplation of nothing serious or Central Park in the dark in “The Good Old Summer Time”!), with Bernstein and the New York Phil:

Another crucial influencer of our musical tastes was Pierre Boulez (see tag). Here he is with the Cleveland orchestra in 1970 in Three places in New England (1911–14) :

That’s a good, wacky start…