“City of Syrup” (or “Syrup City”) is a nickname for Houston that was popularized by Big Moe’s “City of Syrup” (2000) hip-hop recording.
 
The nickname refers to the abuse of codeine-laced cough syrup that was popular in Houston among certain groups of people.
 
     
Urban Dictionary
city of syrup
houston texas wher the sipping of syrup (codiene cough syrup) was made popular. Largely associated with rap artists dj screw, big moe, and swishahouse
i’m heading to the city of syrup to pick me up a 4
by BIG MARK Sep 16, 2004
 
US NO DRUGS
Texas: Syrup city
Texas: Syrup city Houston’s cough-syrup abuse raises questions on links between entertainment and risky behavior.
 
For decades, residents who love this city have searched for catchy phrases to convey its spirit to outsiders. “Houston’s hot,” “Expect the Unexpected,” and “Houston: It’s worth it,” are familiar attempts. None really caught on, so it’s disturbing to learn that for a growing national subculture, Houston has earned a well-known nickname: “City of Syrup.” It alludes to the abuse of codeine-laced cough syrup that, in conjunction with a homegrown music style, has become an epidemic.

According to a 2003 study, one-quarter of at-risk students surveyed in Harris County had used cough syrup recreationally at least once. Ten percent reported using it in the last 30 days. That number has grown higher in the past year, according to an unpublished survey by the same researcher, Dr. Ron Peters of the University of Texas School of Public Health.

While any new drug trend deserves concern, Houston’s cough syrup epidemic involves an unusually troubling element. According to Peters, syrup abuse has grown directly as a result of a Houston-born hip-hop style called “screw,” in which songs are slowed to imitate codeine’s narcotizing effect.

Popularized in the 1980s by the late Houston disc jockey known as DJ Screw, the music is gaining attention — even critical acclaim — across the country. But with the sound comes a subculture in which teenagers at underground nightclubs sip from plastic cups with Sprite and black-market cough syrup.

Why Houston became the epicenter of this music and its attendant drug fad is a mystery. Interestingly, a recent Houston Press article suggests that syrup abuse was associated with the city as far back as the 1960s, when it was glorified by singer/songwriters here, including Townes Van Zandt.

But Peters and other researchers have found that unscrupulous doctors — sometimes abetted by Medicaid abuse — are among the top sources of illegal cough medicine. Peters notes that prior to his study, little research has been done on Houston’s syrup abuse culture. Knowing more about it should become a city priority. Not only will we learn to combat a dispiriting drug trend. Better understanding the links between art, marketing and substance abuse would help the whole country fight an array of other dangerous behaviors.
 
23 November 2000, New York Times, “Rap Is Slower Around Houston” by Neil Strauss, pg. E3:
“In the city of syrup we like to jam music slow,” raps Big Moe. The line, from his album “City of Syrup,” is as concise a statement of purpose as one is likely to find for one of the most interesting, little known regional genres of popular music today. The city Big Moe is referring to is Houston, and in the last several years music and the drug culture have been colliding to produce what is known as syrup music or Screw music, after the producer who has almost single-handedly popularized the style, D.J. Screw.

The name syrup comes from codeine cough syrup, which has become the drug of choice for part of the Southern hip-hop world. Typically sold in baby food jars for $20 an ounce, syrup is usually poured over ice in a foam-plastic cup and mixed with soda and fruit-flavored candy. A report from the Texas Commission on Drug and Alcohol Abuse cites prescription cough syrup as possibly the fastest growing abused substance in the Houston area. In recent years the drink has given birth to its own sub-genre of slowed-down rap in the South. In videos like “Sippin’ on Some Syrup” by the Memphis rap group Three 6 Mafia, people can be seen with cough medicine in baby bottles.