Easy chip question

[Irish]

I'm trying to build a Midi thru box, and the diagram I have (which is
practically the only one out there!) has a chip drawn with each
out/thru port connected to individual inverter, plus one addtional at the
input end (sorry if the terms aren't right). 
My questions are: this chip (74LS244) has individual inverters, plus also has
additional inverters in it that chain the individual ones together by their
base (? I guess - they are drawn as a triangle, and this comes out the side).
Do I need to use these somehow? 
It confused me because the other chip I looked at for a similar
application (74LS05) did not have this 'chained together' piece. 

Also, (duh question) do I need to supply +V and gnd for the chip to work, or can
it be used as a passive(?) device? 

Sorry if these questions are kinda basic - it's amazing how much you can know
about something and still not know about it....

Thank you, 
Irish