Guitar-to-MIDI conversion in Rakarrack/Guitarix?

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Veerstryngh Thynner
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Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by Veerstryngh Thynner »

Greetings all!

My background is in Trad and Mainstream jazz. My main instrument is electric tenor guitar, but I'd like to give it an authentic tenor banjo sound.

I spent eternities searching for some way or other to get this done: years and years and years on end, actually. But miracles do happen sometimes: a couple of days ago - looking for something entirely different - I came across Bardstown Audio. And they are offering a package of samples entitled Vintage Jazz Guitars and Tenor Banjos.

It's pretty steep in price ($199/£123.13/approx. Euro 147). But the quality Bardstown delivers is stunning, allegedly. So I ab-so-lute-ly want to have this.

Thing is, though, that I don't have previous experience with samples/sampling. I've only just taken my first jittery steps. One of the things I was informed of, however, in another LM forum, is that I'd need a USB Guitar-to-MIDI conversion interface .

As hardware, they don't come cheap either. Someone else suggested, though, that Rakarrack/Guitarix/or maybe both may have Guitar-to-MIDI conversion integrated. And that's what I want to ask you all about.

Is this true?

If it is, would somebody out there please be so kind to explain to me how this works? And, possibly, share what their experience was like?

My platform is Ubuntu DreamStudio 12.04 LTS, AMD Athlon(tm) II P360 Dual-Core Processor × 2. Of the original 4Gb RAM 3.7 are remaining. HDD is 750Gb in total.

I have some experience with Rakarrack. But none, so far, with Guitarix. Still, I'd like to hear about Guitarix too.

Thanks in advance for your help.

tnob
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by autostatic »

It's possible with both rakarrack and guitarix. But it only works with single notes. rakarrack has a great Help page, here's the relevant MIDI section: http://rakarrack.sourceforge.net/midiconverter.html
So connect your guitar to both rakarrack JACK inputs, enable the MIDI converter and connect for example ZynAddSubFX to rakarrack's JACK MIDI MC out port.
guitarix as from version 0.27.x comes with the GxTuner LV2 plugin that can convert audio to MIDI too. Load the plugin in an LV2 host that has MIDI out, ie. Qtractor. When using Qtractor insert the plugin into an audio track. Then connect your guitar to Qtractor and a softsynth to the Qtractor Master ALSA output. Enable the plugin and select SEND MIDI, SINGLE NOTE and FAST DETECTION.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by Veerstryngh Thynner »

Dank je wel, AutoStatic. But let's return to English, so the rest of the world can follow, too.

I never was very good at single-string ('Irish', as it's known in folk circles). Improvising in chords is more my style. So I'd probably be looking at polyphonic guitar-to-MIDI conversion.

I have a hunch that this is going to be hardware instead of software.

On googling guitar-to-MIDI conversion, only Sonuus and Roland will pop up. And especially the former seems to be advertising quite aggressively.

A musical instrument retailer once told me that they ditched Sonuus altogether. Single notes only, of course. But only playing backwards, for some reason. On Ebay, there's no lack of Sonuus on offer.

That'll give you an idea, perhaps.

So Fishman TriplePlay really seems my only option (as advised elsewhere in these pages), I guess. Unless this is monophonic as well...

tnob
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by j_e_f_f_g »

A friend of mine has a Roland MIDI guitar that uses pitch conversion. You should be aware of a couple issues.

1) The conversion process needs at least one cycle of the waveform in order to determine pitch. Higher frequencies, with their short cycles, are tolerable. But when you get down to the lower range of the guitar, there's a very perceptible delay between the moment you pick a note, and its resulting MIDI note. I find it too distracting a delay to play his guitar. It totally throws off my timing, and is very unnatural to a guitarist. (And this conversion is done in hardware). He uses the guitar only in his studio, and deals with the delay by not listening to the Midi track at all while recording. He listens only to the raw sound of his pick on the strings. Then he has to quantize, and manually edit, the midi data to correct all the timing discrepencies between low and high notes.

2) Your picking/fingering technique has to be extremely even and precise (like Robert Fripp). If you don't properly damp adjacent strings, or you draw out harmonics on a note, the conversion process will regard these extra frequencies as additionally picked notes, and you get lots of extranous MIDI notes. My friend calls them "glitches", and he has to manually delete them too.

I think pitch conversion by itself is unusable live, and a major hassle in the studio. You need to do what the synthaxe does (http://en.wikipedia.org/wiki/SynthAxe), and instead have a contact switch on every fret to determine triggered pitch. Then the bridge pickup doing pitch conversion is used only to measure string bending, vibrato, and dynamics (ie, "loudness" of the note).

Before investing in a MIDI guitar, you best try it first. The reaction of most guitarists I know to the pitch-to-midi units is "How the hell does anyone play this?", as he picks a note and hears a split second delay plus maybe an extraneous note sound.

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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by AnthonyCFox »

j_e_f_f_g wrote:I think pitch conversion by itself is unusable live, and a major hassle in the studio.
That's no longer true with the Fishman Triple Play https://www.youtube.com/results?q=Fishm ... a=N&tab=w1

Though from reading reviews the build quality seems to be a bit inconsistent and there are some other issues that are typical of a 1st gen product. Hopefully, next year these bugs will be worked out.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by raboof »

j_e_f_f_g wrote:I think pitch conversion by itself is unusable live
Likely true
j_e_f_f_g wrote:and a major hassle in the studio. (..). The reaction of most guitarists I know to the pitch-to-midi units is "How the hell does anyone play this?", as he picks a note and hears a split second delay plus maybe an extraneous note sound.
This depends: you might not need real-time. If you just want to record a MIDI track, you can simply record the audio track on electric guitar like you always do, and afterwards convert it to MIDI. You don't always need do use the MIDI conversion while playing.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by j_e_f_f_g »

AnthonyCFox wrote:That's no longer true with the Fishman Triple Play
I've heard the hex pickups (separate pickup per string) really improve tracking, but there's a practical limit to how quickly a dsp algo can detect pitch (1 cycle -- maybe half a cycle if the shape of the waveform is known and predictable). So those low guitar pitches are troublesome. It's hard to discern from the videos, but I seem to see/hear a very slight delay. In one video review, the guy mentions he has to edit the MIDI track to "correct timing errors and false triggers" which he admits are "things you get with MIDI guitars". How well someone relates to a midi guitar depends a lot on how easily he's thrown off by timing delays, and even moreso how precise/even his picking/fingering technique is. If you're as precise as Robert Fripp (check out the super-clean high-speed arpeggiation on "Frame By Frame" -- he's a human sequencer), or have the string damping dexterity of Alan Holdsworth (no one does legato better), you'll do well. Otherwise, you could hate MIDI guitars... and a lot of guys I know who tried have. (I have a friend who recorded Lou Reed. Lou was experimenting with a midi guitar, and got so frustrated he literally threw it in the trash).

That said, this is clearly a very esoteric "boutique" music product. $400 is right at the bottom of the scale for this sort of thing. I'd be shocked if they were handmade at that price. They probably contracted out one small (like a couple hundred units) production run. It's doubtful you'll ever see a cheaper version. In fact, if the first run takes a long time to sell, there may never be a second run. Happens all the time in the boutique music market. If you want one, better get it now.

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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by tramp »

AnthonyCFox wrote:
j_e_f_f_g wrote:I think pitch conversion by itself is unusable live, and a major hassle in the studio.
That's no longer true with the Fishman Triple Play https://www.youtube.com/results?q=Fishm ... a=N&tab=w1

Though from reading reviews the build quality seems to be a bit inconsistent and there are some other issues that are typical of a 1st gen product. Hopefully, next year these bugs will be worked out.
Have you ever check it out by yourself, or do you just referring to some vid/reviews?
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by AnthonyCFox »

tramp wrote:Have you ever check it out by yourself, or do you just referring to some vid/reviews?
There is a significant amount of information available on the internet about the Triple Play in forums and store reviews, I'm sure you can find anything you want about it with search. It's a pretty hot item.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by tramp »

AnthonyCFox wrote:There is a significant amount of information available on the internet about the Triple Play in forums and store reviews, I'm sure you can find anything you want about it with search. It's a pretty hot item.
Ha Ha, so lets add a bit of this "significant amount of information available on the internet about the Triple Play in forums and store reviews" here. It surely doesn’t matter if it is second or first hand knowledge.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by AnthonyCFox »

It's polyphonic, low-latency, and usb and midi standards compliant. From the forum posts I've seen the hardware works in Linux (and on paper it should). The software only runs in Win7 but it isn't a necessity.

In concept it's a pretty simple piece of gear. It's taken 30 years for it to become a practical reality, so clearly the technical challenges haven't been trivial. It gives guitarists the same instrument choices that have been only accessible to keyboard players until now. And compared to $$Roland$$ products the price is eminently reasonable, and those products don't even compare in latency and sensitivity. If I wasn't such a broke-a** loser I'd have one by now. :cry:
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by tramp »

As jeff already pointed out, there are still some simple physical borders you cant break. So to detect a note and convert it to midi, the note must pass by, in the full length (minimum the half, if you are willing to accept wrong notes in order to improve speed) of it's wave. That mean you have to accept a delay/glitches. I've played around a lot with audio2midi algorithm and have a lot of fun in using it. But, for professional live performance I will consider it unusable, with the exception of a short improvisation to entertain/surprise the visitors.
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by AnthonyCFox »

tramp wrote:As jeff already pointed out, there are still some simple physical borders you cant break. So to detect a note and convert it to midi, the note must pass by, in the full length (minimum the half, if you are willing to accept wrong notes in order to improve speed) of it's wave.
Well, if you watched any of the videos I linked to it'd be obvious that isn't the case. Nor has it been for quite awhile. I wish I could find a really good reference on pitch prediction. I've seen articles on it over the years and there's a fair amount of discussion on various forums (V-Guitar, KVR, Presonuus, etc.). Anyway, Roland has been doing it for years and the Axon was doing it before that. The Triple Play has perfected it.

You guys are stuck in the '80's when it comes to guitar to midi conversion. Watch a video, it clearly works. :roll:
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by tramp »

The question seems to be what you would accept as "perfect" :wink:
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Re: Guitar-to-MIDI conversion in Rakarrack/Guitarix?

Post by AnthonyCFox »

tramp wrote:The question seems to be what you would accept as "perfect" :wink:
Oh. I get it, you're trolling.

You got me. Ha. Ha. Ha. :|
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