This category includes styles as diverse as doo-wop, early rock and roll, novelty songs, bubblegum music, folk rock, psychedelic rock, baroque pop, surf music, soul music, rhythm and blues, classic rock, some blues, and some country music.

Golden Oldies usually refers to music exclusively from the 1950s and 1960s. Oldies radio typically features artists such as Elvis Presley, Chuck Berry, The Beatles, Jerry Lee Lewis, The Beach Boys, Frankie Avalon, The Four Seasons, Paul Anka, Neil Sedaka, Little Richard and Sam Cooke; as well as such musical movements and genres as early rock and roll, rockabilly, doo-wop, soul music, Motown, British Invasion, early girl groups, surf music, teen idol singers, teenage tragedy songs, and bubblegum pop. Music from the folk revival and instrumental beautiful music are among the most commonly excluded recordings from the oldies era.

Most traditional oldies stations limit their on-air playlists to no more than 300 songs, based on the programming strategy that average listeners and passive listeners will stay tuned provided they are familiar with the hits being played. A drawback to this concept is the constant heavy rotation and repetition of the station's program library, as well as rejection of the format by active listeners. This can be avoided either through the use of a broader playlist or by rotating different songs from the oldies era into and out of the playlist every few weeks.

Oldies has some overlap with the classic hits and classic rock formats. Classic hits features pop and rock hits from the early 1970s to early 1990s, while classic rock focuses on album rock from the late 1960s to 1990s (sometimes playing newer material made in the same style as the older songs). As formats have drifted in time with their target audiences, classic hits and classic rock have moved further away from pure oldies, which has largely remained a static format.

The term "oldies" in the early days of the rock era and before referred to the traditional pop music songs of previous decades; a 1953 record review in Billboard describes 1925's "Yes Sir, That's My Baby" as an "oldie." Oldies is known for the near-total and sometimes arbitrary exclusion of some acts that were very popular in their time, including The Osmonds and Barbra Streisand.

The oldies format began to appear in the early 1970s. KOOL-FM in Phoenix became one of the first radio stations to play oldies music, at that time focusing on the 1950s and early 1960s.

In the 1960s, very few top 40 radio stations played anything more than a few years old. In the late 1960s, a few FM stations adopted top 40 formats that leaned towards adults who did not want to hear the same 30 songs repetitively but also did not want to hear music featured on Middle of the road radio stations. They mixed in oldies with their current product and only played new music a few times an hour. These radio stations were often referred to as "gold" stations. Some AM radio stations also began to employ this format. There were also syndicated music format packages such as Drake-Chenault's "Solid Gold" format, frequently used on FM stations that needed separate programming from their AM sisters (due to then-new FCC rules on simulcasting), that functioned as a hybrid of oldies and the adult-oriented softer rock hits of the day. The popularity of the movie American Graffiti is often credited with helping to spur the 1950s nostalgia movement of the early 1970s. It is this movement that gave rise to a number of gold-based stations, such as WHND/WHNE (Honey Radio) in Detroit, WCBS-FM in New York, WQSR in Baltimore, and WROR in Boston, that were classified as oldies stations and not adult top 40. These stations, did play current product sparingly (one or two per hour) throughout the 1970s and into the 1980s; WCBS-FM, for example, played current hits under the moniker "Future Gold" through the late 1980s, and WLNG on nearby Long Island featured a roughly 50/50 mix of current hits and oldies from the early 1960s until about 1999.

Most of these "Solid Gold" stations began to either evolve into other formats or drop the format altogether in the late 1970s and early 1980s. Most AM gold stations flipped to other formats. Some FM stations evolved into adult contemporary stations, including WROR in Boston and WFYR in Chicago. In the early 1980s many AC stations began mixing in more oldies into regular rotation and aired oldies shows on Saturday nights.

Gradually, beginning in 1982, both AM and FM stations began changing to full-time oldies formats. These stations played strictly music from 1955 to 1973, focusing on the 1964–1969 era. Among these oldies stations were WNBC in New York City before 1988, WDRC-FM in Hartford, WODS in Boston, WOGL in Philadelphia, KLUV in Dallas, WWSW in Pittsburgh, WJMK in Chicago, and CHUM in Toronto. Some had as few as 300 songs while stations like WODS and WOGL had as many as 1,500 songs in regular rotation. By 1989, most large and medium markets had at least one, usually FM, oldies station.

This period also saw the rise of syndicated radio shows specifically aimed at an oldies format. They included Soundtrack of the '60s with Murray the K, Dick Clark's Rock, Roll & Remember, Live from the '60s with The Real Don Steele, Cruisin' America with Cousin Brucie, and Rock & Roll's Greatest Hits with Dick Bartley. Most of these shows were three hours long and featured much of the same music from the 1950s, 1960s and 1970s that was in rotation at affiliate stations. All but a few of these shows had ended their run by the mid-1990s, though Bartley's ran into the late 2000s (and eventually returned for several years in the late 2010s) while Clark's show continued until his 2004 stroke and in reruns until 2020.

From 1986 to 1990 several solid gold stations evolved into full-time oldies stations by eliminating current and recent product while also gradually eliminating 1980s songs and limiting 1970s songs substantially. KRTH and WQSR both did this in the late 1980s into the early 1990s. WCBS-FM however continued playing current product in regular rotation until 1988. After that, they played it once an hour between 11pm and 5:30am, until 2001. WCBS-FM also played several 1990s songs per shift during these overnight hours. They also continued to play between one 1980s song every couple of hours to as many as two per hour day and night. WCBS-FM also played from three to five songs per hour from the 1970s. They indeed played more 1970s music than any other notable oldies station. At the same time, WCBS-FM featured slightly more pre 1964 songs than the average station playing as many as five of those per hour.

Oldies stations continued to be late 1960s based throughout the 1990s. WCBS-FM was an exception. Most AM oldies stations also disappeared by the early 1990s except in markets where there was no FM oldies outlet. The format fared well with no end in sight.