licensing – Licence for combination of MIT licenced code

We are about to start a couple of projects for which I have found on GitHub good MIT licenced code which slightly modified and combined together would give us a very nice point to start from. My question is how it works with licences when you combined several code together from different repositories (of different owners). Should I include a separate Lincence for each piece of code? Since it is not an Apache licence code changes notice is not required, but then I was wondering how I would then specify the copyright notice for each piece since the code in the repositories is not used as separate blocks, but combined together.

I am new to this community, I hope the question is not off-topic.
Thanks in advance.