What do we really need to make most types of music? Do we already have them? What's missing /  needs expansion on this lest?
 
DAW
 
FX
EQ
Reverb
Compressor
Expander
Limiter
Chorus
Phaser
Flanger
Delay
 
Synths
Additive Synth
Subtractive Synth
PCM Synth
Vintage Synths
Synth Drums
 
Band
Electric Guitar
Acoustic Guitar
12 String Guitar
Nylon String Guitar
Electric Bass
Acoustic Bass
Drumkit
Saxophones
 
Keyboards
Piano
Pipe Organ
Electric Organ
Electric Piano
 
Orchestral
Solo Strings
Ensemble Strings
Solo Brass
Ensemble Brass
Solo Woodwinds
Ensemble Woodwinds
Percussion
 
Vocals
Male Lead
Female Lead
Male Chorus
Female Chorus
Mixed Chorus
 
World Instruments
 
Cinematic Instruments
 
Renaissance Instruments

talent

Scook's right...

If you have THAT...you don't need anything else...
you can take a FREE DAW with it's stock plugins 
and creat masterpieces....

Then there's the rest of us...

Equipment wise just a penny whistle, that's all but if you want to record it then it gets more complex.

Nice list, huge one!

To the guitars I would add 12 string and nylon string and possibly the Ricky 12.

But what more did they need in the beginning?
https://youtu.be/wqpygx9BRYE

What's required, in descending order of availability:

1. ideas
2. inspiration
3. motivation
4. time
5. freedom from distractions
6. funds

[EDIT]
Sorry. When I first read this thread I didn't notice that it was in the Software subforum. The question should have been "What software do we actually need..."

But it's a sad fact that software is more essential to music production than guitars, drums and keyboards are these days.

The list was motivated by noticing that, especially after buying new glasses, I'm broke but that I have some version or other of almost everything on the list and maybe I don't need GAS so much as using what I have and actually learning how to make music and avoid runon sentences.

I just need this Thermos, and that's ALL I Need!

Genghis
I just need this Thermos, and that's ALL I Need!

Exactly