My kingdom for some basic bass and treble sliders!!

The EQ is great but I dont like having to apply these settings to my entire 4000+ song collection. Yeah, yeah I know there are multiple EQ settings. But I could spend weeks configuring each of them for a particular kind of music, and still not get it right.

I would like to be able to adjust bass and treble individually on the fly.
You know what I mean; turn up the bass for a particular song or album, and then turn the treble up for talk radio or something.
The key here is "on the fly" .
Monkeying around with the EQ while hurtling along at 80mph aint no fun.

Anybody else know what I'm talking about?

Unfortunately I'm totally unqualified to come up with something like this, so I give it to the group.
Could it be a pop up option in Hijack (Perfect!!), or a standalone app?

I know I'm probably totally missing the point of the high quality EQ, and exposing my ignorance.
But, oh well...

Could somebody please help me?
If youre in the Boston area, and you see a black VW Golf driving erraticaly at high speed, with the driver hunched over the radio, thats me modifying the EQ.
Stay away. I'm not safe.

Z~