Should I match key or BPM first when choosing the next track?

Filter by BPM first, then by key. Tempo is the harder constraint because a large mismatch is immediately obvious and difficult to hide, whereas key gives you several compatible options at any given tempo. In practice you shortlist tracks within a few percent of the current BPM, then narrow that list to keys that are the same, one step up or down on the Camelot wheel, or the relative major/minor switch.

What is key-lock or master tempo?

Key-lock, also called master tempo or key adjust, is a DJ software feature that lets you change a track's tempo without changing its pitch. It uses time-stretching to keep the key fixed while the BPM moves. It is essential when you want a large tempo change, such as bridging a 124 BPM track into a 128 BPM track, without pushing the pitch a full semitone out of harmonic range. The trade-off is that heavy time-stretching can introduce audible artifacts, so most DJs use key-lock for moderate shifts and keep large jumps to transitions where a slight texture change is acceptable.

Can I mix two tracks with the same key but very different BPM?

You can, but the tempo gap has to be bridged. Two tracks in the same key still need their beats aligned, so you either pitch one toward the other (using key-lock to protect the key), use a halftime or double-time relationship where 70 BPM lines up against 140 BPM, or ride the transition through a breakdown where the beat drops out. Sharing a key makes the blend sound musical, but it does not remove the need to reconcile the tempo.

How do I sort my DJ library by key and BPM?

First make sure every track has an accurate key tag and BPM value written into its metadata. Then, in Rekordbox, Serato, Traktor or Engine DJ, add both a Key column and a BPM column to your track list and sort by one then the other, or use smart playlists and filters to build tempo-banded, key-grouped crates. A common setup is to sort primarily by BPM range and secondarily by Camelot value, so within each tempo band you can see all the harmonically compatible options at a glance.

Key and BPM: The Two Pillars of a Clean Transition

Q: What is the difference between key and BPM in DJing?

BPM (beats per minute) is the tempo of a track, and it determines whether two songs can be beatmatched to play in time. Key is the musical scale a track is built on, and it determines whether two songs sound consonant when their melodies and basslines overlap. Beatmatching aligns rhythm; harmonic mixing aligns pitch. Strong DJ transitions use both: a compatible tempo so the beats lock, and a compatible key so the harmony does not clash.

Q: Does changing the BPM of a track change its key?

Yes, unless key-lock is enabled. When you speed a track up or slow it down using the pitch fader, you stretch or compress the waveform, which raises or lowers the pitch and therefore the key. As a rule of thumb, roughly every 6 percent of tempo change shifts the pitch by about one semitone, which moves the track two positions around the Camelot wheel. Enabling key-lock (also called master tempo) changes the tempo while holding the original pitch, so the key stays put.

Q: How much can I pitch a track before the key changes?

About plus or minus 3 percent is usually safe: the pitch shift is small enough that the track is still effectively in its original key for mixing purposes. Beyond roughly 6 percent the track has moved close to a full semitone and is now in a different key, which breaks harmonic compatibility unless you account for it or turn on key-lock. Most club-standard beatmatching happens inside the plus or minus 3 to 6 percent window, which is why small tempo nudges rarely cause key clashes.

Every smooth DJ transition rests on two numbers: the tempo (BPM) and the musical key. Tempo decides whether two tracks can lock in time; key decides whether they sound in tune together. Get one right and the other wrong and the mix still fails. This guide shows how the two pillars interact — including the way pitching a track changes its key — and how to build a library you can navigate by both at once.

Updated 28 July 2026 · ~9 minute read · Maintained by the OpenKeyScan team.

In one paragraph

A great transition needs a compatible tempo so the beats line up and a compatible key so the harmony agrees. Filter your next track by BPM first (usually within ±3–6%), then narrow to a compatible key — the same Camelot value, ±1, or the relative major/minor switch. Remember that pitching a track changes its key: roughly every 6% of tempo shift moves the pitch about a semitone, so use key-lock when you need a bigger tempo change without breaking the key. All of this depends on accurate key and BPM tags, which is exactly what a dedicated analyzer like OpenKeyScan writes into your files.

Two numbers, two jobs

DJs talk about "mixing in key" and "beatmatching" as if they were separate skills, but in a real set they run at the same time. Each pillar solves a different problem, and neither one can cover for the other.

BPM — the rhythmic pillar

Beats per minute is the tempo. If two tracks are far apart in BPM, their kicks and snares drift out of phase and the blend collapses into a mess of double-beats. Matching tempo is what lets you overlap two records for eight, sixteen or thirty-two bars without the groove falling apart.

Key — the harmonic pillar

The musical key is the scale the track is built on. When two overlapping tracks are in clashing keys, their basslines and melodies produce dissonance that listeners feel as tension even if they can't name it. Matching key — harmonic mixing — keeps the overlap sounding musical.

Beatmatch a key clash and you get two grooves locked in time but fighting harmonically. Key-match a tempo clash and you get two consonant tracks whose beats never sit together. Only when both pillars line up does a transition disappear — which is the whole point.

The hidden link: pitch ties BPM to key

Here is the part most beginners miss. On a classic pitch fader, changing tempo and changing pitch are the same action. Speed a record up and it plays higher; slow it down and it plays lower. That means the moment you nudge the tempo to beatmatch, you also nudge the key.

The relationship is roughly linear. A useful mental model: every 6% of tempo change equals about one semitone of pitch, and one semitone equals two positions around the Camelot wheel. So a small ±3% beatmatch nudge leaves the key essentially where it was, but a big tempo grab pushes the track into a genuinely different key.

Tempo change	Approx. pitch shift	Effect on key
±1–3%	up to ~½ semitone	Effectively the same key — safe to treat as unchanged
±3–6%	~½ to 1 semitone	Drifting; borderline for tight harmonic blends
±6%	~1 semitone	Now a different key — moves 2 spots on the Camelot wheel
±12%	~2 semitones	A full whole tone away — key relationships are scrambled

Figures are approximate. The exact math is that a semitone is a pitch ratio of about 1.0595, i.e. ~5.95% — which is why "6% per semitone" is the handy shorthand.

Key-lock: change tempo without breaking key

Every modern DJ platform has a feature to break the pitch-tempo link. It goes by different names — Key Lock in Serato and Rekordbox, Master Tempo in Traktor and on Pioneer/AlphaTheta CDJs, Key Adjust/Key Shift in Engine DJ, and Master Tempo again in VirtualDJ. Under the hood they all do the same thing: time-stretch the audio so you can move the tempo while holding the original pitch.

With key-lock on, you can drag a 124 BPM track up to 128 BPM to meet the next record and its key stays exactly where it started — no accidental semitone drift, no broken harmony. The catch is quality: aggressive time-stretching introduces artifacts (a slightly "phasey" or grainy texture), which is worse the further you push. Practical guidance:

Small nudges (±3%): key-lock optional. The pitch shift is inaudible for mixing, so leave it off if you prefer the natural sound.
Moderate shifts (3–8%): key-lock on. This is where it earns its keep — you protect the key with only mild artifacts.
Large jumps (>8%): key-lock keeps the key but the stretch becomes audible. Reserve these for transitions through a breakdown or FX wash where a slight texture change is hidden.

The both-pillars workflow: BPM first, then key

When you are choosing the next track live, filter in the order that removes the most bad options fastest. Tempo is the harder constraint — a big mismatch is instantly obvious and hard to hide — while key usually leaves you several good choices. So filter by tempo, then by key.

Read the current track. Note both numbers, e.g. 8A at 124 BPM.
Band the tempo. Shortlist tracks roughly within ±3–6% (here, about 120–131 BPM) so you can beatmatch without a drastic pitch change.
Filter that band by key. From the tempo-compatible tracks, keep the same Camelot value (8A), ±1 (7A or 9A), or the relative switch (8B).
Decide on key-lock. If the best musical pick needs more than ~6% tempo change, enable key-lock so pitching it doesn't also move the key.
Confirm in headphones. The numbers narrow the field; your ears make the final call on energy, vocals and groove.

This whole loop only works if the metadata is trustworthy. A wrong key tag or a half-time BPM reading sends you toward "compatible" tracks that aren't — which is why analyzing your library with an accurate detector is step zero. Download OpenKeyScan to write correct keys into every file, then let your DJ app read them.

Sorting your library by key and BPM

The fastest way to mix on both pillars is to prepare your crates so both numbers are visible and sortable. Every major platform supports Key and BPM columns — the trick is to sort by tempo band first and key second, so within each band you can instantly see the harmonic options.

Software	Key-lock name	Sort-by-both approach
Rekordbox	Key Lock	Add Key + BPM columns; use a Smart Playlist filtered by BPM range, then sort by Key
Serato DJ	Key Lock	Show Key + BPM columns; Smart Crates on BPM range, sorted by Key
Traktor Pro	Master Tempo	Enable Key + BPM columns; use the tempo/key filter panel to narrow
Engine DJ	Key Adjust / Key Shift	Smart Playlists on BPM band; sort within by Camelot key
VirtualDJ	Master Tempo	Filter folders by BPM, then sort the Key column

A common pro setup is 4–6 BPM-wide bands (e.g. 120–124, 124–128, 128–132) with tracks inside each band sorted by Camelot value. That layout mirrors the both-pillars workflow directly: you glance at the band that matches your current tempo, then read down the compatible keys. For a deeper walkthrough of the tagging and crate structure, see our guide to organizing a DJ library by key.

Typical tempo ranges by genre

Knowing where genres sit helps you plan tempo arcs and spot the half-time/double-time tricks that let distant BPMs meet. These are broad, working ranges — plenty of tracks live outside them.

Genre	Typical BPM	Halftime pairs with
Hip-hop / trap	70–100 (140–160 double)	Drum & bass, footwork
House / tech house	120–128	—
Melodic / progressive	120–126	—
Techno	128–140	—
Trance	132–140	—
Drum & bass	170–178	Hip-hop, half-time bass

The halftime column is where key and BPM get creative: a 172 BPM drum & bass track and an 86 BPM hip-hop beat share a pulse, so if they also share a compatible key you can layer them convincingly. Same key, "different" tempo — bridged by the 2:1 relationship.

Common key-and-BPM mistakes

Pitching hard with key-lock off. Grabbing 5–8% of tempo without master tempo quietly pushes the track a semitone or more, and your "harmonic" pick is now a key clash.
Trusting a half-time BPM reading. Detectors sometimes tag a 140 BPM track as 70 (or vice versa). A wrong BPM ruins tempo banding — verify outliers.
Ignoring key because the tempo matched. Two tracks locked in time can still fight harmonically. Both pillars, every time.
Over-relying on key-lock for big jumps. Past ~8% the time-stretch artifacts become audible; hide large tempo moves in a breakdown instead.
Building crates on bad tags. Sorting by key and BPM is only as good as the underlying metadata. Re-analyze with a tool you trust before you lean on the sort.

Frequently asked questions

What is the difference between key and BPM in DJing?

BPM is the tempo, and it decides whether two tracks can be beatmatched to play in time. Key is the musical scale a track is built on, and it decides whether the two sound consonant when they overlap. Beatmatching aligns rhythm; harmonic mixing aligns pitch. Strong transitions use both.

Does changing the BPM of a track change its key?

Yes, unless key-lock is on. Pitching a track up or down with the fader stretches the waveform and shifts the pitch. Roughly every 6% of tempo change moves the pitch about a semitone — two positions on the Camelot wheel. Key-lock (master tempo) changes tempo while holding the original pitch.

How much can I pitch a track before the key changes?

About ±3% is safe — the shift is small enough to treat the key as unchanged. Beyond roughly 6% the track is close to a full semitone away and is effectively in a new key, breaking harmonic compatibility unless you use key-lock. Most beatmatching happens inside the ±3–6% window.

Should I match key or BPM first?

BPM first, then key. Tempo is the harder constraint because a big mismatch is obvious and hard to hide, while key usually leaves several compatible options at any tempo. Shortlist tracks within a few percent of the current BPM, then narrow to compatible keys.

Can I mix two tracks with the same key but different BPM?

Yes, but the tempo gap must be bridged: pitch one toward the other with key-lock on, use a half-time/double-time relationship (70 against 140), or ride the transition through a breakdown. Sharing a key makes the blend musical but doesn't remove the need to reconcile tempo.