MIDI instruments aren't necessarily always in perfect tune, as Mac pointed out, many better synths include the inconsistencies of the instruments they are emulating.

My wind controller has a 'reed' that senses pitch, which is almost as difficult as a saxophone to keep in perfect tune (although it is easy to keep it in close tune). However, if the patches are programmed properly, changing pressure on the 'reed' not only changes the pitch, but changes the timbre of the instrument tone just like the instrument that is being emulated. This is done through physical modeling synthesis on my VL70m module.

I know from basic analysis that a guitar is not in tune and from working with a strobo-conn in school that it takes a lot of work to play a saxophone in tune. I exploit these when emulating those instruments with a synthesizer.

I recorded a guitar emulation I did with my WX5 controller and VL70m synth - recorded at a gig on an Archos "juke box" device (pseudo iPod). I posted it on the Gibson/Epiphone forum and asked the guitarists to evaluate my guitar playing. I got plenty of great comments, including one that said it sounded very Jeff Beck-ish (to me a huge compliment - as I admire his technical skills).

After a few dozen comments I came clean and told them I played it on a wind synth, and people were amazed. After the 'confession' one guitarist said that he thought there was something a little be funny about the vibrato.

Rolling Stone magazine classified Edgar Winter's solo in Frankenstein as one of the 100 greatest guitar solos in rock. And Edgar played it on an analog synth - the ones with oscillators, filters and all those twirly knobs.

You can make convincing emulations of acoustic instruments - but you have to know how to play the synth patches to do it, and each patch is different.

When doing brass sections, I often mess with the intonation of the instruments 'stretch tuning' them in a way. Or for another example, if I am playing two trumpets or saxes together, I'll attempt to get them to play together in just intonation as two might do if they are focused listening to each other. Of course, that means one of them is out of tune with the band - but that's OK.

The problem is that it is so easy to get sounds out of a synth, that way too many people play those synths without learning how to do it well. Especially with a sequencer. In the early days of MIDI on the Internet, I downloaded a few MIDI files from the usenet/newsgroup forums as it seemed like a great way to get these Steely Dan songs for my duo without the time spent sequencing them myself. What I found was robotic sounding, step-entered from the sheet music. Easy to do, but not very musical. I did some more downloading and found everything from more step entered music to music so badly played it was laughable.

It's been my experience that the easier the entry level is for an instrument, the greater the number of people who don't play it well but play for the public anyway. With those great numbers of mediocre players, it gets easy to dis the instrument.

So just because a synth patch may be perfectly in tune, that doesn't mean it has to be played that way. That's where skill, practice, musicianship and taste come into play.

Bob "Notes" Norton smile Norton Music
https://www.nortonmusic.com

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