The B side on a vinyl record is the second side of a physical record, opposite the main or A side. On vinyl, each side holds a separate groove, so the B side can carry its own distinct recording, with its own title, artist, and running order. Historically, the B side provided space for a secondary track, outtake, or demo, often less polished than the A side single. Over time, B sides became a place for experimentation, alternate mixes, or complementary material, and they remain a tactile, intentional part of the vinyl listening experience.
Origins and Historical Context
B sides emerged with the commercial rise of 78 rpm shellac discs and later long-playing vinyl records in the mid-20th century. As physical constraints required artists to choose one or two songs per side, labels began designating a primary track as the A side and the secondary track as the B side. The format encouraged more diverse track placement, and B sides offered a practical solution for releasing additional material without the cost and production overhead of a full single or album.
By the 1960s and 1970s, the B side was culturally significant, particularly in pop and rock markets. DJs, collectors, and radio programmers treated the A side as the hit and the B side as the secondary offering that could include deep cuts, live versions, or experimental pieces. Even when airplay focused on the A side, the B side became an important part of an artist’s catalog and a driver of record-collecting culture.
78 rpm Era
Before the LP, 78 rpm discs typically held one major track per side, with the B side used for a second, often related, song. These early discs were fragile and expensive, so B sides needed to justify their place. The practice of assigning a B side helped standardize how recordings were packaged and sold by the minute and by the side.
The Long Play and the Album-Oriented Shift
The introduction of the 33⅓ rpm long-playing record in the late 1940s increased available space per side, allowing longer compositions and multiple tracks. While LPs emphasized album sides, the concept of an A side and B side remained useful for singles pressed on vinyl, even when those singles were part of a larger album release.
Technical Definition and Physical Implementation
On vinyl, music is stored in a spiral groove that runs from the outer edge toward the center. Each side of the record contains one continuous groove, so the A side plays from the outer edge inward, then the record must be flipped to play the B side. The grooves encode stereo or mono audio through physical modulations, which means every detail of the cut affects loudness, frequency response, and surface noise. This makes side length and track sequencing deliberate choices in manufacturing.
Because each side is limited by groove spacing and maximum playable duration—typically around 22 minutes for 12-inch LPs at standard levels—labels plan B sides carefully to avoid distortion or excessive inner-groove compression. This technical background explains why some reissues feature shorter B sides or careful track placement to preserve audio quality.
Practical Ways B Sides Appear on Vinyl
On a standard 7-inch 45 rpm single, side A carries the main single, and side B often houses the B side track. On 12-inch LPs, sides may be designated as A and B, and each side can host multiple tracks. In these cases, the label may refer to the ‘A side’ as the first physical side and the ‘B side’ as the second physical side, regardless of how many tracks each side contains.
Common B Side Configurations
- Single with two tracks: One A side, one B side.
- EP or promotional single: Multiple tracks across A and B sides, with one side treated as primary.
- Album-oriented LP: Sides labeled A and B for packaging and DJ continuity, while all sides contain album material.
Labeling and Cataloging B Sides
Vinyl labels use a clear notation so that the B side is unambiguously identified. For a standard single, you will see something like:
Side A: Artist — Title (Catalog Number)
Side B: Artist — B Side Title (Catalog Number)
For albums, the catalog number and matrix numbers may appear on both sides, with ‘S1’ and ‘S2’ or ‘1A’ and ‘1B’ etched into the runout grooves. Collectors rely on these markings to verify pressing variants, identify test pressings, and ensure accurate cataloging in databases and marketplaces.
A Side Versus B Side in Practice
While the A side typically carried the intended ‘hit’ or lead track, the B side offered distinct practical and artistic roles. In many cases, the A side was tailored for radio play and chart eligibility, while the B side allowed artists to include songs that did not fit strict single formats. Over time, this created a tradition where B sides are valued for rarity, experimentation, and historical context.
The table below summarizes common differences and their implications for listeners and collectors.
| Attribute | A Side | B Side | Source Type |
|---|---|---|---|
| Typical role | Primary single or lead track | Secondary track, outtake, or experimental piece | Industry convention |
| Chart eligibility | Usually designed for chart tracking | Rarely eligible on its own | Label practice |
| Production priority | Higher production and promotion focus | May be lower budget or live | Label resources |
| Collector interest | Core commercial product | Sought for rarity, alternate mixes, and B-side artwork | Collector market |
| Duration limits | Fits within side-time constraints (often | Fits within side-time constraints | Technical limitation |
Collecting and Cultural Value
B sides contribute significantly to vinyl culture, especially among collectors and fans who value physical media. Alternate mixes, studio chatter, radio edits, and live recordings often appear on B sides, making them essential for a complete discography. In some cases, a sought B side can drive the value of an otherwise common single, especially when the B side features a rare or previously unavailable recording.
Artwork and packaging also matter. Vintage B side labels often include distinct artwork or color variations, and promotional copies may feature custom stamps or stickers. For many collectors, documenting B side variations is a core part of cataloging a record collection, and databases that track matrix numbers and runout etchings help verify authenticity and pressing details.
Modern Releases and Digital Context
Although digital streaming has reduced the functional role of sides, B sides remain relevant in vinyl reissues, special editions, and archival releases. Labels sometimes include bonus tracks on the B side of LPs to maintain physical exclusivity or to present a more authentic version of an album. For audiophiles and crate diggers, the B side is a tangible part of the listening ritual, from checking runout codes to aligning the stylus at the correct groove start.
When evaluating releases, pay attention to catalog numbers, matrix marks, and side duration. These details help confirm whether a pressing is an original, a reissue, or a budget variant, and they clarify how the B side fits into the broader discography.
Wrap-Up
The B side on a vinyl record is more than a historical footnote; it is a functional part of vinyl’s physical design. Whether used for alternate mixes, deep cuts, or exclusive material, the B side enriches the listening and collecting experience. Understanding how B sides are labeled, produced, and valued helps you get more from your records and better appreciate the depth of a vinyl collection.
FAQ
Reader questions
Can a B side be just as popular as the A side?
Yes, some B sides achieve lasting popularity through radio edits, dance remixes, or standout performances, even when they are not marketed as the lead track.
Do all vinyl singles have a B side?
Not all. Some promotional or one-sided test pressings omit a B side. Many modern 7-inch singles, however, retain the tradition of placing a secondary track on the B side.
Are B sides included when streaming an album?
Streaming services often include B side tracks when they are part of the original album or single listing, but tracks exclusive to the B side may appear only in compilations or expanded editions.
Why do some B sides sound quieter or compressed?
Inner-groove distortion and lower signal levels can make B sides sound quieter, especially near the center of a 12-inch record. Proper cutting and mastering can reduce these effects.
How can I identify a B side on a record?
Check the label for markings like ‘Side B’ or catalog suffixes such as ‘S2’. Matrix numbers etched near the center or runouts often clarify which side is which.