In today's technically advanced world, what we did back in the late 60's would probably seem somewhat ordinary, but at the time, it created a bit of a stir.  In order to understand what I am talking about, you need to know the difference between telephones then and now.

First of all, there are some real fundamental differences between the "old" phones and today's phones.   In the 60's a phone was a phone.  Nothing more.  They were used to make and receive phone calls.  No fancy stuff.  But, on the other hand, they nearly always worked.  No dropped calls.  No funny sounding calls.  They just worked.  All the time.  The following quote from Wikipedia: 

While POTS (Plain Old Telephone Service) provides a relatively limited feature set, low bandwidth and no mobile capabilities, it does provide (in most geographic areas) much greater reliability than any of the more “modern” telephone systems (wireless, cellular, VoIP, etc). This can be illustrated with the following demonstration: pick up a standard “old-fashioned” telephone and dial a valid number - you will, nearly 100% of the time, be connected to the desired party (provided they are available). This is more than can be said for any almost other communication system.

The other thing that was not common then was what we call "three way calling" where you could have more than one party on the line at the same time.  These "conference" calls had to be set up in advance with the phone company and they would connect the parties for the call.   Because of this, what we did was a little complex at the time.

We essentially took two phone lines, dialed a number on each one, and then patched the two lines together so each person thought the other one had placed the call.  The ensuing confusion was what was fun.  Many of these (we called them "Daily Doubles") I recorded, and they are now here for all to enjoy.   These were all done on the UPS campus, and the "victims" were various students picked at random.   In order to add to the confusion, we tried to pick phones that were in the same Fraternity house, Sorority, or study complex so the people connected might know each other.

In order to pull this off, it was all done on a phone that was uniquely modified to be able dial separate numbers on different lines and then connect them, with a tap to feed an amplifier and speaker so we could listen to, and, obviously, record, the ensuing fun.  I still have the phone -- here is a picture.

The "victims" of these pranks may have long forgotten them, but if by chance you are one of the featured voices, or know one of them, I would love to hear from you and I will give full credit to those who endured our pranks. 

Now, enjoy the following clips.

This call was to the Pi Phi Sorority.

Another call to the same two phones in the Pi Phi Sorority.

And now to the Frat houses, with a call to Sigma Nu.

From there we go to Beta Theta Pi.

 And now on to Theta Ki.

Back to the girls dorm with Sandy and Janice.

And one final visit to Sandy and Janice.