X The Unknown

X is typically used as the variable (the unknown quantity) in algebraic equations. According to this post by Dr. Ali Khounsary of the Argonne National Laboratory in Argonne, Illinois, one possible reason why the letter X is used to denote the unknown factor in algebraic equations dates back to the origins of algebra itself in Arabic civilization. Dr. Khounsary writes:

Algebra has its roots in the Middle East where sciences including mathematics and astronomy flourished in the Islamic world in the 700-1450 period. Muhammad al-Khwarizmi (780­-850) was one of the major mathematicians of his time and the author of a number of influential books. One of his major books is on arithmetic and another on algebra. In fact, it is his transmuted name ‘algorithm’ which we now use to refer to the step-by-step procedures for solving a problem. His algebra book is titled Kitab al-jabr wal-muqabala which translates to “the book of calculation by completion and reduction.” The Arabic word “al-jabr” is the origin of the word “algebra” which describes the process of moving terms from one side of an algebraic equation to the other to find the value of an unknown. . . .

In algebraic equations, one solves equations to obtain the value(s) of one or more unknown(s). The word for “thing” or “object” (presumably unknown thing or object) in Arabic—which was the principal language of sciences during the Islamic civilization—is “shei” which was translated into Green as xei, and shortened to x, and is considered by some to be the reason for using x. It is also noteworthy that “xenos” is the Greek word for unknown, stranger, guest, or foreigner, and that might explain the reasons Europeans used the letter x to denote the “unknown” in algebraic equations.

Xenos, of course, is the root of the word xenophobia: the fear of foreigners or strangers. Interestingly, as it happened, the call letters of all Mexican radio stations—also referred to as “border radio”—begin with an X. The first Mexican radio station, located in Reynosa, started broadcasting in 1930, with the call letters XED, possibly a pun on “crossed [Xed] out,” a reference to the marginalized and dispossessed. Only one major company uses X in its name—Xerox—and very few bands have used X in the group’s proper name—X-ray Spex (a play on "X-ray Specs," ads for which used to appear in comic books, pictured), the L. A. punk band X, and XTC come to mind—and very few albums and songs have used X in the title. One should perhaps remember that X is also an abbreviation for Christ, as in “Xmas,” and that once John Lennon named an album Shaved Fish, perhaps a play on ICTHUS, the Greek word for “fish”—ICTHUS being an acrostic referring to Jesus Christ, the Son of God.

Some Albums:
Electric Light Orchestra, Xanadu
David Lindley, El Rayo-X
Iron Maiden, The X Factor
Olivia Newton-John, Xanadu
Def Leppard, X
Mushroomhead, XX
Toto, XX (1977-97)
ZZ Top, XXX

Some Songs:
Blondie, “X Offender”
Coldplay, “X & Y”
John Lennon, “Happy Xmas (War Is Over)”
Mushroomhead, “Xeroxed”
Olivia Newton-John, “Xanadu”
Rush, “Xanadu”
System Of A Down, “X”
U2, “Xanax and Wine”
Frank Zappa, “Project X”
ZZ Top, “Heard It On The X”

Border Blasters

“Border blasters” is the phrase broadcasters use to refer to the so-called “X stations”—Mexican radio stations—because the call letters of every Mexican radio station begins with an X. Otherwise known as border radio, perhaps the best known of the border blasters was station XERB, the model for the station featured in George Lucas’s American Graffiti (1973). Peculiar to the United States, border radio inspired countless rock and pop musicians, as the Mexican stations largely played music suppressed by the corporate owned, commercially oriented radio stations in the United States: not only were countless teenagers able to hear country and western, played by the likes of the Carter Family (pictured on the CD cover of Vol. 3 of the XET recordings) and Hank Williams, but blues musicians such as Howlin’ Wolf and John Lee Hooker. George Lucas, born in 1944 and raised in Modesto, California, grew up listening to the Xs, many of which featured eccentric disc jockeys such as Wolfman Jack, who would eventually make an appearance in American Graffiti. Lucas was one of those kids who listened to “50,000 watts out of Mexico,” as the Blasters sing in “Border Radio.”

As Gene Fowler and Bill Crawford point out in their book Border Radio, Mexican radio stations developed in the late 1920s as a response to monopolistic American and Canadian corporations carving up the frequencies—in doing so, shutting out Mexico—and, subsequently, in the 1930s, to federal regulations that required standardization of the format and proscription of the content. Station XED, in Reynosa, began transmitting in 1930. Fowler and Crawford write:

The men who first moved to the border began their broadcasting careers when the federal regulatory agency was but a twinkle in Herbert Hoover’s eye. These media trailblazers deeply resented the monopolistic power of the networks and the increasing government interference in their activities. They traveled from the hinterlands of Iowa, Kansas, and Brooklyn to a territory beyond the pale of American law, a sparsely populated land of ocotillo, grapefruit, and Angora goats—la frontera, the border.

Border radio operators came up with a unique method of sidestepping U.S. broadcasting restrictions: They built their stations just across the border, in Mexican territory, and worked out special licensing arrangements with the broadcasting authorities in Mexico City, whom they found to be much more agreeable than the stuffed shirts at the Federal Radio Commission. Like all radio stations licensed in Mexico, the border stations were given call letters beginning with XE, a brand that added to their mystique. To compete with the wide coverage of the established multistation networks, these operators created what were essentially single-station networks, stations with such extraordinary power that their signals could cover much of the United States and, in some cases, most of the world. Border radio operators accomplished this feat by hiring expert engineers to build special transmitters. While most radio outlets in the United States broadcast over transmitters with about 1,000 watts of power, border stations boomed their programming across America with transmitters humming at as much as 1,000,000 watts [station XERA].

Essential Recordings (with thanks to Mike Jarrett)
ZZ Top, “Heard It on the X” Fandango (Warner Bros., 1975)
Warren Zevon, “Carmelita” Warren Zevon (Asylum, 1976)
The Blasters, “Border Radio” The Blasters (Slash, 1981)
Wall of Voodoo, “Mexican Radio” Call of the West (I.R.S., 1982)
Dave Alvin, “Border Radio” King of California (Hightone, 1994)

Essential Viewing
American Graffiti (1973)
Border Radio (1987)
Pump Up the Volume (1990)
Empire of the Air: The Men Who Made Radio (Ken Burns, 1991)