Edited slightly to add reference numbering ...

The fact is that I would like to know several aspects regarding the operation of the libraries such as:

(1) if I can load from each library only the performances that interest me so as not to occupy more space than necessary,

(2) if I can listen / try them before loading them to decide which ones charge and what not

(3) or if on the contrary I have to load complete libraries and go testing all the sounds and then delete them one by one those that I do not want to keep ...

(4) I don't know if there is any tutorial available where all this management is discussed.

I'll start with (4) - there's not a tutorial that directly answers your questions as asked. Some tutorials are references along with discussion can be found here: https://www.yamahasynth.com/ask-a-question/modx-library-management-reference-materials

(1) You can load only portions of Libraries that interest you. Not in one step however. Not without external tools (on a PC/Mac). So assuming only MODX - what you would have to do is load the Library in its entirety, backup your current user area (if there's anything there you want to keep), then initialize your user area (wipe it clean), then import FROM your Library (-or- Libraries) TO your user area all of your "keepers". Then you can erase your librar(y/ies). Your user area now has all of your keepers. Then create a Library file from your user area. Then install (load) this Library of your custom keepers.

Alternatively, you could purchase software that allows for you to take library files and remove/reorder/etc. Performances inside this library file offline. Then install the new library that was edited with the software tools. The tools available are primarily available as J Melas tools as the most officially suggested tools out there. The others probably are not worth mentioning - so I'll leave it up to you to track down other options.

(2) You cannot listen to libraries on MODX before installing. There is not a preview. If the samples are not encoded with "fancy" encodings (which serve to copy protect them as one function) - you may be able to preview the sounds using the J Melas tools. There are plenty of examples of samples that cannot be previewed with these tools as they only support straight-forward sample encoding. Your other option is finding youtube or website previews of sounds. Most content providers have some form of preview. Although not all. And keep in mind that libraries are distributed from multiple channels (different websites) and each website may have a different level of preview content. I understand this is different from you being in control - you hear what someone else plays and possibly with other sounds combined (drums, etc) - but it's one of the options available.

(3) Yes - this (loading them on MODX, deciding, and keeping) is what you need to do if your only tool is MODX.

One more note:

If you're concerned about the amount of space a Library consumes - and already know that all of the Libraries you want to load won't fit in 1GB - keep in mind that removing Performances from a Library does not necessarily make the Library smaller.

A Library with no samples is not going to take up "any" space at all. If a Library is going to impact the 1GB - it's going to be its samples that take up this space. Say you have a Library with 50 different piano Performances and the Library takes up 600MB all on its own. It's too big to fit with your other libraries. Deleting 25 Performances from this Library does not make the Library consume 300MB. In fact - if all of the Performances reference the same set of samples - then deleting 49 Performances (and leaving just one) will not de-reference the 600MB of samples that are used in each Performance. What I'm saying is that deleting Performances may remove clutter (Performances you don't want) but may not have an impact to space used by the Library in any meaningful way.

Some Libraries have a big collection of different instruments where each Performance may reference a different set of samples. In terms of size, these types of Libraries would benefit more from removing Performances. In order to know how the Library is constructed - you have to do some scuba diving. Or take a shotgun approach and cross your fingers.

Software tools would help you "see" inside a Library.

Overall, this is an area of growth for Yamaha as traditionally (and the tradition continues) file management is a weakness in terms of ease-of-use. Yamaha's approach is to keep the interface very close to the underlying hardware instead of abstracting the complexity and proving easy manipulation tools on par with modern consumer-friendly devices.

I'm not a fan of "dumbing down" interfaces in general. Synth programming shouldn't have a ton of abstraction. But the filesystem is one of those areas where it doesn't serve to have a programmer's approach.

Thanks Jason!
Your explanation has been very enlightening. The feeling I had before your explanation was that Yamaha in this regard was not friendly, and I am afraid that it is. With kronos, it's all incredibly easier and practical. I guess there is no perfect Synthesizer!
On the other hand, I can think of a last alternative to not have the worry of space limitation and therefore not have to manage the presets (performances) in such a laborious way and at the same time of doubtful result ... I ask, let's see if possible...
It would be possible to use a large capacity pendrive (for example 64gb) as an external hard drive and load libraries directly from it and select the performances to be able to use them in the same way as if they were in the user memory of the MODX? I do not know if it is a sovereign nonsense what I am saying, or if it makes sense. I simply try to find solutions to the limitations of the machine. Maybe I'm throwing a lot of imagination!
This possible solution, in my case, would entail another problem, and I could not use the USB port to use the Alesis Vortex controller in a wireless way ... But that is another story ...

Thanks for all your help. Very thankful!

What you are missing is a positive approach to using your Library space. Surely, the advantages outweigh the hassle, as this feature allows the user to customize 1GB of the instrument’s Waveform data. This allows you to extend the instruments resident Wave ROM to 6.67GB. I’ll take the Reese’s tag line to say... “Not Sorry!” With great power comes greater responsibility... the good news is you have the ability to pick and choose what gets installed in your Library area, the bad news is you have to actually pick and choose that data. Again, “not sorry!”

Being able to customize the Waveform ROM from which you can build sounds has long been a dream of professional musicians. Here’s what you need to know.

Libraries like the Bosendorfer Imperial 290 and the Chick Corea Mark V are specialty SINGLE instrument Libraries. In other words, if you decide to use the approx 400MB that each of these Libraries will occupy, know that every one of the provided Performances utilizes the same Waveform data. So you don’t save any memory by just selecting a few Performances

The Performance data without the Waveform is only a few kilobytes of data, while the instrument’s audio data is over 400MB. These two libraries feature just one meticulously sampled instrument each!

Libraries like the CS80 and MONTAGE XPANDED are different in that they offer a wide variety of instrument sounds sampled, as opposed to one instrument done in meticulous detail. It is your choice to decide what data you would like to keep resident in your instrument.

Generally speaking, handling the data and compiling their own custom Libraries is what the “target customer” for the MONTAGE/MODX wants. The MONTAGE/MODX customers wants to customize, pick and choose, and even edit the purchased data.

What you can do
Load the “KApro_CS80” Library it provides 164/640 Performances. You will want to take your time and play all 164 Performances. As you go through them decide on the Performances that you must have resident in your instrument. Those are the ones you will use to create your own customized version of the File. You can do so by either Loading the data to a LIBRARY, and mark just the ‘keepers’ - Import them to your User area and make a customize Library file. Although the CS80 data is 470MB total, it is used to create 164 Performances. Using “Library Import” will allow you to choose just the data that you want from the provided file.

Load the “MONTAGE EXPANDED” Library is 256 Performances... again being a variety of instruments made from the data, you would use “Library Import” to move those items for your custom Library into the current USER BANK. If you have, for example, selected 100 from the CS80 Library to Import to User, you could add your selections from this Library — assembling them to the User Bank. It is the User Bank that gets ‘saved as...’ a new Library file.

Load the BOSENDORFER Library it provides 16/640 Performances. You might as well keep all 16 Performances. If you decide this is an acoustic piano you must have resident in your instrument. Install it and don’t worry about managing which of the 16 Performance you wish to keep. Discarding the ones you don’t like will not SAVE ANY WAVEFORM MEMORY

Load the CHICK COREA MARK V Library it provides 16/640 Performances. You might as well keep all 16 Performances. If you decide this is an electric piano you must have resident in your instrument. Install it and don’t worry about managing which of the 16 Performance you wish to keep. Discarding the ones you don’t like will not SAVE ANY WAVEFORM MEMORY.

Don’t let the assembly of data for your own Library throw you. It is worth the effort — that’s all you need to know.
The Melas Waveform Editor allows you to do all the assembly on your computer, and is the elegant option for management of your custom data. Those who use it find it extremely cool. And don’t let anyone discourage you from working with this feature (it’s not for everyone, but those who want to customize their instruments, it’s worth the time invested).

USER and LIBRARY Files

Thank you very much Bad Mister!

I think I understand it much better now, and it's very good news of course! Sorry for my awkwardness, the truth is that I have a hard time understanding certain things, first by Google Traslator, and second because it is not a friendly language for me.
So, if I have not misunderstood, the libraries do not occupy user space, but the contents (performances) that I choose to import into my user area, if I do not copy that content from the library to the user area, it is like the content which the Modx brings from the factory in the Rom. Therefore, if I only use Modx for everything, I can "preview" the sounds in the library itself and choose which one of them took them to the user area, and those that didn't, I delete them .... I think!
Ups, I'm sorry! It costs me a lot!

In other words, libraries do not take up user space, if I only use their presets without editing them. And if I edit a performance of a library, this performance is the only one that occupies a small part of 1 Gb of user space that is available. This is so?

Library data that has custom Waveforms (samples) use up your 1GB of allotted space. Whether you edit them or not.

A Performance containing custom Waveforms that is in a Library uses up some of 1GB. This means if you load the KApro_CS80 Library... each of the Performances in that Library will point to a Waveform in the 470MB of Library Memory designated “KApro_CS80 Bank”

If you wish to only use some, not all of the KApro_CS80 data, you can use “Library Import” to select just the Performances you want from that Library... it not only moves the Performance to the User Bank, but it makes a COPY of the Waveform and any assigned custom Arpeggio, and places those copies in the User Waveform area and the User Arpeggio area.

Once you have *imported* the Performances to the User area, you can DELETE the installed LIBRARY.
This will leave just the Library Imported versions of the KApro_CS80 — which now are contained and pointing to USER Bank locations. If you look on the OSC (Oscillator) screen you will see the items you have imported no longer reference the LIBRARY Waveforms, instead they reference the USER area for Waveforms...(the copies). Delete the LIBRARY

Now you can SAVE what’s in your USER BANK as a new (streamlined) LIBRARY FILE. This *repoints* the Elements of the Performances you have selected to a new Library File .X8L... name it “My CS80”... this file is saved to your USB stick... “My CS80.X8L”
This file will contain installable versions of your selected data.

Now when you LOAD this new Library file it will occupy the LIBRARY area, all custom Waveforms will go to permanent Library locations.
Finally, you can Initialize the USER data... clearing the User Bank, for new duties.

Extra Credit:
If you think about the 1GB memory as two lobes of the brain... one is permanent storage, and one is a work area. In this case the data being handled is audio sample data. The permanent storage area (Library) is Read Only Memory. The other area is the work area Random Access Memory (User)... its where you assemble data for you custom Library file.

Let’s say we only want a few selected items from the CS80 Library
When you use Library Import you make a duplicate of the Wave data in the work area. You can then delete the entire installed 470MB of the KApro_CS80 because you have a copy of the Waveform data you need — it’s been imported to the work area (User).

The User area is where you assemble all the data you want to put into YOUR custom Library.
You have well over 1GB of “free” downloaded data... you can pick and choose what data you wish from them and assemble your own LIBRARY. Because a Library can have 640 Performances you can add (via Library Import) data from multiple Libraries into one.

Of course the Bosendorfer and Corea data are huge — and will cause you to pick and choose what you want to install from the other two.

Agree! It is understood!

Thank you!