Fade-in vocals

There is a certain effect in some of the music I listen to that used to intrigue me. It was the sound of the singer’s vocals fading in, as if they were coming to you through some ethereal dimension. I wondered how it was done.

I figured it out at some point. It’s actually quite simple: you reverse the vocal track, apply reverb to it, then reverse it back. I’ve used it several times in my music; here’s an example where I go a little crazy with it (it’s present through the entire song).

Obviously, a computer makes this a lot easier. It must have been a pretty tedious thing back in the days of recording to tape. But maybe there’s another way to do it that I haven’t thought of.