Imagining the Mix Tape, c. 1948

German-American engineer S. Joseph Begun, writing in 1948 on magnetic recording:

In analyzing the particular advantages of the magnetic phonograph, one will first think about its usefulness as a long-playing instrument. While some of the magnetic recordings are now limited to 1/2 or 1-hour recording time, this is not a basic limitation. The playing time, within reason, could be made as long as one desires, for example, as long as the longest symphony ever written, or, if one wants to go to the extreme, even as long as the longest opera ever written... 

Classical music, however, constitutes only one type of musical program to which people want to listen in their homes. There are still many more dance records and light musical selections sold than symphonies and operas. True enough, one could have small reels, each of which would accommodate one tune, but in this case the user would have to change the reels after each playing....No doubt, in time to come, some ingenious engineer will think of a construction that will permit loading a magnetic recorder with a number of reels in such a fashion that after one reel is exhausted the mechanism will automatically seize the recording medium of the next reel, thread it through the system, and start to play it. 

Particularly when tape is used as the recording medium, editing is simple, and it would not require a major effort on the part of the user to join a number of selections together on a large reel, thus achieving a series of preselected short tunes. This method may be the answer, but it is not believed that the average person using such an instrument will subject himself or herself to such trouble, however small it may be. It is because people are by nature lazy that so many gadgets can be sold today, and only an enthusiastic amateur who is willing to add a personal touch to his equipment will go further and record and edit his reels.

S.J. Begun, Magnetic Recording (New York and Toronto: Murray Hill Books, 1949), 222–23. Picture is of a Tonschreiber Type B, a field version of the Magnetophone used by the Nazis during World War II.