ok, listen to the guitar feedback/sustain ride in on this-
[soundcloud]https://soundcloud.com/rlc-ltd/hide-n-seek-live-version[/soundcloud]
then listen to this-
[soundcloud]https://soundcloud.com/rlc-ltd/an-a-chord[/soundcloud]
what I did was cut out just that feedback/sustain part, mix that to a.WAV file,import it to that 1st song, transpose it from A to F#,and adjust to fit the intro timing then fade it in.
I've used that single file manipulated different ways on about 3-4 different songs. it comes in handy when having to direct/silent record @ 3am and you still want a cranked amp harmonic feedback sound.