I wish to get a free software to produce tunes of some sort.
if you happen to chnge your mind about 'free' software, try Adobe Audition.
Sorry, here is the right link: http://www.nch.com.au/tonegen/index.html
NCH Tone/Waveform Generator allows you to play different frequencies. http://www.fpv.umb.sk/kat/kf/Integrovana_prirodoveda/TG/Zvuk/Elektrina_zvuk/Tone%20Generator%20Software%20Download.htm
Audacity can create different tones and sounds, along with editing and many other features. Here is more information about it: http://manual.audacityteam.org/man/Generate_Menu
Here is where you can download it: http://audacity.sourceforge.net/download/
there are loads of ipad apps if you have an ipad. it's really awesome, beatmixer would be my favorite. but i think you were looking for a windows software?
here are some free softwares
There were a variety of recent articles on MUO on how to create your own music:
My personal favorite beat generator is Gnaural. Justin Pot did an interesting article on it a while back:
Hope that helped!
try this site