If all we ever heard was the artist's voice in it's natural state, we'd probably run screaming from half the talent out there. Ahhh...but thankfully there are a myriad of signal processors out there, able to do some amazing things. From pitch correction to compression to reverb...even simple equalization...signal processors have been making artists sound perfect for decades.
And don't think it's just for the studio recordings. Live sound processors do wonderous things to vocals and instruments. Many of our favorite effects, like The Edge and his ubiquitous delay pedal or Dimebag Darrell's dual Whammy pedals are both examples of live sound processors doing their thing.
In the end, we have producers and engineers to thank..or not...for making the music palatable. While it's true that some of it is overproduced, most often, they add the touches with various effects and signal processors that make the artist be all they can be...even if it takes a little help!
All prices are in USD.