How a DJ prepares a set, and how to organize your music so the preparation is fast

Preparing a DJ set is the work done before the night: choosing which tracks are in play, deciding the order they are likely to go in, and checking that the order works — for tempo, key and energy — while there is still time to change it. How much of that a DJ does varies enormously, from a folder and a feel to a fully ordered list, but the three stages are the same, and each one is only as fast as the library underneath it. This is what each stage needs, and how to organize your music so that it is already there.

Stage one: narrowing the library to the night

Nobody prepares a set from their whole collection. The first thing an experienced DJ does is narrow: this venue, this slot, this crowd, this month's new music. What comes out is a pool — thirty to sixty tracks for an hour is common — that is larger than the set but much smaller than the library.

What makes this stage fast is that the library already knows what the DJ is about to ask it. Three pieces of information do most of the work:

• Genre or style, so a house night does not start with a scroll through drum and bass.
• Energy, as a number per track, so the warm-up pool and the peak-time pool can be different pools.
• Recency, so the tracks bought this month are one click away from the tracks played for years.

None of these are exotic. They are a genre field, an energy tag and a date, and the whole of "how to organize music for DJing" reduces to making sure all three are filled in and searchable.

Stage two: the order

With a pool, the DJ puts tracks in a likely order. Not the final order — the room will change it — but a spine: where the set starts, where it should be at the half, what the last three tracks could be. The shape of that spine depends on the slot, and how to structure a DJ set covers the shapes; what matters here is what the ordering stage needs from the library.

It needs the same numbers, per track, that the set is judged by. BPM, so a jump of more than a few percent is visible before it is audible. Key, in one notation the DJ can read at a glance — CamelotA 24-position circle that turns every key into a short code like 8A or 9B. or Open KeyThe other short key notation, using m and d where Camelot uses A and B., not a mix of both — so two neighbours that will clash are visible too. Energy, so the arc the DJ intends is the arc the numbers describe. A track that carries all three can be placed in a minute; a track that carries none has to be listened to again, which is the slow part of preparation and the part good organization removes.

Stage three: checking before playing

The last stage is the one that separates a prepared set from a hopeful one: the DJ looks at the order as a whole and asks whether it works. Does the energy climb where it should, or lurch? Do the peaks land in the right third? Are any two neighbours fighting harmonically? These are exactly the questions listed in is my DJ set in the right order, and they are answerable on paper, by ear, or by a tool — but only beforehand. After the first track plays, the only fixes left are the ones you can do live.

This is also where a written plan pays for itself. A DJ who prepared an ordered list can check it in ten minutes. A DJ who prepared a folder cannot check anything, because a folder has no order to check.

Organizing your music so all three stages are fast

Put together, the stages ask the library for five things per track: genre, energy, BPMBeats per minute: a track's tempo, and the first number any DJ looks at., key and a date. Organizing music for DJing means getting those five into fields that your software can sort and search, and then keeping them there.

Let the software fill what it can. Rekordbox, Serato and Traktor all detect BPM and key on import; you do not need to type those. (If you are still choosing between them, that is a separate decision, and not one this article makes for you.) What none of them fills is energy, because the ID3 standard has no energy field — every tool that writes one has borrowed some other field for it.

Pick one field for energy and stay in it. Mixed In Key writes to the comment field; Rekordbox users often use Grouping; Traktor has a second comment field. Any of them works, as long as your whole library uses the same one — because the field decides whether the value travels when you move software or export a playlist. Which tag each program keeps energy in lists the options and which ones survive an export.

Pick one key notation. A library where half the keysThe note and mode a track is written in — what decides whether two tracks sit well together. say `8A` and half say `Am` is a library where clashes hide. Convert once, in whichever direction your eyes prefer, and stop.

Build pools, not just playlists. A playlist is an order; a pool is a set of candidates. Keeping a warm-up pool, a peak pool and a closing pool — by energy band, refreshed as music comes in — means stage one is already done when a gig is booked.

Prune the misses. A track that has been in the pool for a year and never made a set is taking up scrolling time. Move it out. The library that prepares a set fastest is not the biggest one; it is the one with the least in it that will never be played.

Where a tool fits, and where it does not

A tool can do the third stage and speed up the second. DropThe moment a track releases all its energy, after the tension that built up to it. an export into the free energy curve tool and it reads the order, the energy values and the keys, draws the curve the set makes, and flags the jumps and the clashes — no account, and your audio never leaves your machine. It reads a Rekordbox XML, a Traktor NML, an M3U8 or a folder of tagged files, so it works on whatever your organization produced; the import formats page says what each carries.

What no tool does is stage one. Choosing which sixty tracks belong to this night is the DJ's taste applied to a room, and it is most of what "preparing a set" means. The library organization above does not replace that judgement; it makes sure that when the judgement is made, the numbers are already there to check it.