There are probably people here who could be of more help, but I will do my best to clearly answer your questions to correlate with my own experience, and I hope it'll help you.
1. I know that a midi keyboard is a piano like instrument that you connect to your pc and are then able to press keys on the keyboard and have the sounds come out of the pc speakers. that of different musical instruments like voices on a piano keyboard as long as you have the VST on your pc and a door? like reper or logic pro on the mac, my question is if all I want to do is to play and here those VSTS not recording and other audio editting stuff, how would I go about doing so? and am I actually correct so far in my asumtions?
I just want to nitpick on one minor thing, the term is DAW (D A W, short for digital audio workstation) not door. This is an important term used in this field so I thought you should be aware of it and what it stands for.
That out of the way, you have the right idea. ?Strictly speaking, a midi keyboard sends messages saying, "I played this note" and "I pressed it this hard" and "I moved this wheel/slider" or whatever. These messages it sends are called midi messages and they go to wherever your DAW is directing them.
Most DAWs such as Reaper, Logic etc. can use plug-ins of some sort. On Windows, VST (virtual studio technology) plug-ins are often used, I think on Mac the format is called AU (audio unit), though I think? they support VST as well, I dont' use Mac so I wouldn't know. While the two formats are different, they have similar functionality, it's just different standards they use, so far as I know.
But DAWs don't just have to use plug-ins, they can also direct other hardware. For instance, I have a Korg synthesizer with no keyboard, it's literally just a box I hook up to my computer which can play different sounds. So it's not too useful on its own, but I can use my midi keyboard to play the sounds.
All keyboards these days are going to be midi compatible unless you get a toddler's toy. So no matter what keyboard you get, you will be able to do what you're asking about, and in many cases, more. But some keyboards have their own built-in sounds. With these keyboards, you can still use sounds from VST plug-ins and other hardware as I said above, but in addition you can use the keyboard's own built-in sounds to create your tracks. For me, this is how I prefer to work, and if you can afford a keyboard with high quality sounds you enjoy to work with, then it's a worthwhile investment. Keyboards with their own built-in sounds range in price from a couple hundred bucks for entry levels, to $5000 and beyond for the most professional keyboards, and due to their popularity they are getting better all the time as new models are made. Granted, keyboards with their own built-in sounds are still more expensive than a strait-up midi keyboard that doesn't have any sounds on it. The latter tend to run pretty cheap, so if you don't care so much about built-in sounds and functions, a midi keyboard would be better for you. I don't have experience with these types of keyboards though, so I can't recommend a favorable one.
I don't expect you to perfectly understand what I am saying. I have purposefully kept it vague and generalized. What I am basically trying to tell you is that all keyboards send midi messages, and all synthesizers and plug-ins can work with these messages in at least some basic way. These things are pretty standard, so once you learn the basics, your knowledge will carry over into your new endeavors. As for specific methods for doing x y and z, I won't go into that right now as I find those kinds of explanations difficult to understand unless someone is trying to help you with your specific setup.
2. related to first. if I am correct that all I need is vst, for playing and a software like reper, where would I obtain them? free would be prefered to begin with? and yes I would need a midi keyboard, I guess I'll grab one off of amazon.
See above for answer.
Also a few points specifically about Reaper and VSTs. Reaper is technically free, it is a 60-day trial but will just constantly nag you afterward to purchase. It won't restrict your usage though. That said, the price is very reasonable, (around $60 iirc). I would also highly recommend the free Osara add-on, as it allows you to use many functions in Reaper which are very difficult to use otherwise.
If you're on a Mac, you could still use Reaper but I've been told that Osara for Mac isn't nearly as efficient as it is on Windows. And if you're going to go the Logic route, I've been told Logic accessibility is workable but the impression I am getting is that you have to have the patience to know its qwirky rules, and that it's not perfect. I could be wrong, however. As I say, I have no Mac experience.
VSTs range in price too, from free to a few hundred dollars. But there are plenty of free ones out there, especially if you are into electronic stuff. The free stuff for acoustic instruments is a pretty mixed bag though, and when you deal with acoustic instruments it tends to get more complicated anyway since you sometimes have to load large files containing the instrument data into the plug-in. This introduces some accessibility hurdles, depending on what you're trying to use.
3. If I want to learn more, such as say learning to play cords, or adding multiple tracks together and or how to play other musical instruments along with the terminology, what would be a good starting point?
Sounds like you are asking two different things here: How do I learn more about playing music, and How do I learn about using a DAW? These are two different bags I'm afraid. If you want to improve your keyboard skills, or learn to play other instruments, piano lessons or lessons on other instruments may be a good option. You could try some Youtube tutorials on various topics you are interested in. They can be a good start if you find good ones. I listen to them myself sometimes when I am curious about some aspect of an instrument.
There are some audio fundamentals courses for blind Reaper users. They aim to familiarize you with Reaper workflow, and just getting you familiar with audio in general. I haven't really scoured the net for these courses. Furthermore I don't know how many of them actually cover making music as you want to do; most of them deal with audio production for podcasts and the like. Also, for me at least, making music is kinda complicated since I don't find Reaper intuitive for making the music. I end up linking to another program (QWS) for handling the midi data and using Reaper just to make the sounds available to it. But that's a different topic for a different day I think.
Sorry I've thrown all this at you and made it sound so complicated! It doesn't necessarily have to be, there is such a thing as keeping things relatively simple. But I don't know exactly what you want to do, so I'm throwing a big bulk out there. Also I've tried to pave my own road when working with this stuff so not many perople had the patience to teach me, so it's kind of a mess for me to sort out and try to explain. Hopefully I have helped you a little though, and I am available if you want to talk about these things.
Make more of less, that way you won't make less of more!
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