Sorry, it does not look as if the Pyle you listed has any MIDI connections.
I really do not know of any Soundblasters that have MIDI either. Old ones did, but that was a different connection than the usual 5-pin midi type cord connection.
Mics can be XLR connection (like on the Pyle) or dynamic mics which may be 1/4" connection like a guitar cord type cord.
And without having the Soundblaster card listed to be known, the only ones I have seen just can not be used for a microphone. But there is also volume on the computer, for line inputs and mic volume, but as I said, usually the mic used (which is different than a regular microphone) is only a computer mic and that is the difference. They just do not sound great but are a really cheap condenser type mic. Just for talking usually.
So that leaves what kind of recording do you want to acheive?
Are you trying to do the recording all at once? (the cheapest audio/interface usually let you have two inputs, L and R, for recording one track at a time, but the DAW (Sonar- Music Creator 6 say for example) can record the next track, and the next track up to a total I think of 32 audio tracks, and usually more Midi.
Now if you get good sound out of your synth, you do not have to use midi at all and can use the audio output to record from. After all if you use midi, then the only thing on the computer to use for midi is microsoft's soft wave table synth that is like GM with its sounds, and it does not sound that good at all. Now you can record midi and send the track recorded back out to the midi synth and use the sound there, but again, if you want to make it all in the recording, then you have to record it back into audio anyway, or use what is called a soft synth sound that some are included with the DAW (Sonar - Music Creator 6). DAW means Digital Audio Workstation - which is your computer you are using after setting it up to record music ( which usually means not being on the Internet or having Wi-fi interfere with it) and all automatic functions of the OS not interferring, or setting up the computer as a recording computer. Don't worry, it can be used any other way also, just streaming audio or video needs to have it work without causing dropouts or latency from some other hardware device (like Wi-fi) or program interfering with the running of the computer while recording and or listening to music. (that may well be another subject but there is always search on the Internet or help here to find out if something is going wrong.
http://www.thesycon.de/deu/latency_check.shtml a free program that can be download to see if there is a problem with streaming audio or video (needed for recording music or video whatever).
Now, an audio/interface can be a kind of mixer, but really is not, unless you buy one with more channels, usually to record a live band or a real drum set, or something of that nature which has more inputs and or outputs to feed to music monitors or just plain old computer speakers not built into the computer but usually separate or both or even 3 of them. Whatever.
So there is always equipment out there that will do about anything but then there is the price of it all in the first place.
Take for instance me recording on my computer - I do at the most 2 tracks at once (L and R) and may record a synth part, then I go back after that is done, and get the next tracks ready to record for a new part (arm them) and record perhaps a bass part, then go back and record a drum part, or several drum parts, and then take two other tracks (all recordings on different tracks - up to 32 tracks total in Music Creator 5 or 6 - more can be done with a more expensive version of Sonar say like, and then by the end I have all the parts I want to use, and usually add the vocals last.
So, yes, you can use a mixer (like a live band mixer) or not, but an audio/interface can have more than two inputs, and usually the inputs are for anything, like a mic, a guitar, or a synth to begin with. There is more but that involves digital signals and usually ADAT is used but in the end:
you need a pre-amp to make the microphone loud enough to record to begin with (either needing 48 volts or not depending on microphone used) or something for the guitar to boost the signal to acceptable levels to record ( or use a guitar amp that is mic-ed to record the guitar, bass amp for bass, or like I do since I have to - use my synth for sounds (not guitar though or voice).
It is not that you can not probably use the Soundblaster if you have the correct connections (and adaptors can be bought to connect to about anything) but it is limited in the way it usually is connected usually by 3.5mm mini plugs (stereo) like used on a iPad or the small connector used to plug headphones into something.
The audio/interface usually uses the regular connections for mic or guitar or synth and the outputs may also be the 1/4" (guitar cord type or balanced cord which is like a stereo headphone cord but only for one channel -which is another type cord usually used in recording to keep out extraneous noise in the recording.)
So with that, and perhaps adaptors to connect whatever cord to what is in the unit, the general usage way of cords for anything in music equipment is better with the audio/interface (plus they usually sound better in the end for the recording afterwards).
midi is used by people who have software samples on their computer to input a midi part or edit it, and then use a software sample of a sound to make it into audio to play back the part. The only problem with that is if you use too many software sounds on the computer, it can make the computer lag which then has latency and all the sounds do not come out at the same time.
When recording audio the regular way (plug in a guitar and go, or a synth audio outputs and go or a mic input and go) then latency can be way less and then with ASIO drivers instead of Windows OS drivers there is no latency because the ASIO drivers given by the manufacturer account for latency so all the parts are heard at the same time.
Soundblaster has ASIO drivers, it is just that the inputs are not as good as an audio/interface and the connections are not convenient to use and in the end usually does not sound that good. A cheap audio/interface will sound better I would think although I have not used them all that is for sure.
What Gregy57 mentioned usually are a modest price audio/interface that can be used and get very good results recording.
Examples:
http://www.sweetwater.com/store/detail/FCA610/ http://www.sweetwater.com/store/detail/Scarlett2i4/ Now some which are cheaper do not have midi connections, and some cost a lot more.
I can not recommend any because I use an RME Babyface (and hopes it lasts for about 10 years).
Some may last longer than others and some may have manufacturers that keep up the drivers for new OSes that come out and all of that.
There are others, but look at the front and back usually for all the connections an audio/interface will have.
Usually there is the front combination connector (take a mic, take a guitar, takes a synth) for any regular input but do not used anything but rounded end cords (not Hosa cords they get stuck in the connection and either you have to take the unit apart to get it out, or perhaps even break the connection). There is a difference in cords, some cords are more rounded on the tip end (like on a guitar cord the very tip end) and some are not (like the Hosa cables).
But that is about it, and sell what you do not use and probably be more satisfied then trying to hook up with adaptors into a Soundblaster card (even if it does have midi) unless it is a EMU Creative Lab Card which is an audio/interface, but some people do not like them even if that is used.
http://www.creative.com/emu/products/usbinterfaces/ These are the audio/interfaces from Creative Labs (Soundblaster with the gaming and regular just-so sound card for computers).
Maybe you can use one of those and trade in the one you got, unless you got one like in the link above. Where they sell those, I do not know, but somewhere can be searched probably on the Internet. How much they cost and really how they sound - well that is another subject, and maybe there are reviews on the Internet about any of that that can be searched for and found.
And you have to check (once again stated) to see if the audio/interface has all the connections you need (usually midi is not on cheaper audio/interfaces) to make sure you get what you need. And will have the drivers for the computer you have. Creative Labs is I guess pretty good with that although it has been some years since I used one of their cards (audio/interface ?) to record anything through.
And then you can play and record that music, musicmama!