I believe I’ve written this before:
In the Mir yeshiva, on Yomim Noraim, they don’t sing anything. When Darchei first started having a minyan for the Yomim Noraim, R’ Bender shlita asked R’ Shmuel Berenbaum zt”l if Darchei (which considers itself an offshoot of Mir) should also not sing. R’ Berenbaum replied that people today need singing to stay involved in the davening – without it, they tend to “space out” and can’t concentrate for the entire time.
This was said for the Yomim Noraim, but perhaps it applies for other times as well?