The Tape That Made Pop Music: How 2-Inch, 16-Track and 24-Track Reel-to-Reel Recording Changed Everything

If you've ever listened to a rock or pop album from the late 1960s or early 1970s, you were likely hearing the direct result of a technological shift that happened in recording studios. Before this shift, music was captured in real-time, all at once. After it, artists could layer sounds, correct mistakes, and build complex sonic landscapes. This revolution was powered by multi-track tape recording, specifically on 16-track and 24-track reel-to-reel machines using 2-inch tape.

Here's the story of how these machines changed the music industry forever.

The problem: the "live" limit

Before the mid-1960s, most popular music was recorded in "live" sessions. A band would set up in a studio, play together, and the engineers would mix the sound in real-time onto a two-track tape (one channel for left, one for right). When they didn't have a mixer they would experiment with placing instruments various distances from a single mic.

This had major drawbacks:

• No edits: if a drummer missed a beat during the chorus, the whole band had to re-record the song.
• No overdubs: you couldn't easily add a guitar solo later. If a singer wanted to harmonize with themselves, they had to stand next to other singers.
• No flexibility: once the tape was cut, it was done.

Why 2-inch tape?

The width of the tape matters. 2-inch tapes were already an available format for Ampex video recording technology, whose R&D was conducted at the Ampex lab in Redwood City, California. It was then adopted for audio. It is twice as wide as 1-inch tape and four times the width of half-inch. 1-inch also came from the video world and was an upgrade from 2-inch tape there, since it was more compact and cost less. 1-inch would go on to be used for 8-track and later 16-track audio formats.

This wider tape allowed for:

• More tracks: you could fit 16 or 24 individual audio lanes side-by-side.
• Better sound quality: wider tape means less noise and higher fidelity.
• More dynamic range: the recording could handle wider dynamics without distortion.

The invention: introducing "tracks"

The solution was multi-track tape invented by Les Paul. Instead of recording everything onto one or two channels, Paul experimented with sound-on-sound recording, and then with a tape head with 4 tracks, where each track on the head could play or record independently from the other tracks on the head. Machines like the Ampex MM-1000 and Studer A800 could be configured with interchangeable head widths and track configurations.

• 4-track machines arrived in 1954 with machines like the Ampex Model 300-4.
• The first 2-inch multitrack audio tape machines with both 8 and 16-track arrived in 1967 with the Ampex MM-1000, which featured interchangeable heads.
• The first dedicated 2-inch 16-track machine arrived in 1968 with the MCI JH-5.
• 2-inch 16-track and 24-track configurations for the Ampex MM-1000 came out in 1969, and the MCI JH-16 arrived in 1971.
• More 2-inch 24-track machines came later in the 70s and 80s like the 3M M79 in 1971, Stephens 821-B in 1974, Otari MTR-90 in 1979, and MCI JH-24 in 1980. The Studer A800 from 1978 and Ampex MM-1200 from 1976 could both be configured with 8, 16 or 24-track 2-inch heads.

By the 1970s, 16-track and 24-track machines became the backbone of professional recording. These machines allowed producers to record drums, bass, guitars, keyboards, and vocals on separate tracks. This meant they could adjust the volume, tone, and effects of each instrument independently during the mixing process.

How it changed the recording industry

1. The rise of the "producer" as artist

For the first time, the recording studio became an instrument. Producers like George Martin (The Beatles), Brian Eno (U2, David Bowie), and Phil Spector could manipulate sound in ways that were impossible live. They could layer vocals, create soundscapes, and experiment with effects that didn't exist in the physical performance.

2. Complexity and layering

Bands could now record songs that were too complex to play live. Consider:

• Pink Floyd's Dark Side of the Moon: used 24-track tape to create intricate sound effects and layered vocals.
• Led Zeppelin's Physical Graffiti: allowed for complex drum overdubs and multi-layered guitars.
• Michael Jackson's Thriller: used multiple 24-track machines in sync with each other using a method engineer Bruce Swedien named the "Acusonic Recording Process", which was just syncing the two machines' SMPTE timecode to build massive 48-track sessions with multiple vocal tracks and percussion parts.

3. Flexibility and perfection

Artists could now "fix it in the mix." If a singer hit a wrong note, they could re-record just that vocal track without re-recording the entire band. This led to the highly polished, "perfect" sound that became the standard for pop music in the 1980s and beyond.

Why it matters today

Even though we now record digitally on computers (DAWs like Pro Tools or Logic), the workflow of modern recording is still based on the 24-track tape model.

• Separate tracks: we still record drums, bass, guitars, and vocals on separate lanes.
• Overdubbing: we still add instruments and vocals after the initial recording.
• Mixing: we still adjust each track independently.

The 2-inch, 16- and 24-track tape machine didn't just change how music was recorded; it changed how music was composed. It turned the studio into a creative playground, recording layer by layer, creating the rich and complex recordings we know today.

The legacy

While analog tape has largely been replaced by digital recording, many studios still use tape emulation plugins to capture the warm harmonics of 2-inch tape. Moreover, the philosophy of multi-track recording, breaking a song into its component parts and building it up, remains the foundation of modern music production. Recently, many engineers and producers realized another benefit was the need to commit to tape. The capability of endless tracks and recording time we've had available since non-linear digital recordings means wasting time trying to get everything perfect or over experimentation.

In short, the 2-inch, 16- and 24-track tape machine gave music its depth, complexity, and flexibility. It transformed recording from a documentation of a live performance into an art form in its own right.

Still have the tapes?

Those reels are now 40 to 55 years old, and the ones from the 1970s and 80s are the most likely to need baking before they can be played at all. We transfer 2-inch 16- and 24-track, 1-inch 16- and 24-track, 1/2-inch 8- and 16-track and 1/4-inch reels, with every track captured as its own file.

Send a track sheet if you have one — it is what tells us which lane held which instrument. If the session was recorded with noise reduction, we decode Dolby A, SR and dbx rather than guessing. Not sure what you are holding? Start with what kind of tape do I have or the recording and tape transfer glossary, then contact us.

Once the tracks are digital, moving them between studios is its own problem — one the industry has only recently started solving properly. See the DAWproject format for how a whole session now travels between DAWs.