TJ Hertz, the English DJ and producer known as Objekt, lives a few stories up in a backhouse apartment in Neukölln, Berlin, where I met him one hot and rainy morning this past July. We were both a little groggy—it was just a few days after Freerotation, which he'd played and I'd attended. Hertz made himself eggs and we chatted for a bit, mostly about the festival, where he's performed every year since 2013, and where, over the years, I'd watched his style as a DJ evolve. His first set there was a vicious blend of techno, electro and post-dubstep—this was the era of Cactus , his breakthrough 12-inch on Hessle Audio. By 2014, a more unusual sound was taking shape. Hertz punched into the 150 BPM range for a good chunk of his set, which he later described as " the most fun I can remember ever having as a DJ ." The following year he closed the festival with a party-rocking tear-out that the writer Rory Gibb likened to "dancing inside a jet engine."At this year's Freerotation, a few days before we sat at his kitchen counter, Hertz delivered a set that was both more understated and more radical than any I'd heard from him before—smooth and intuitive, yet totally unpredictable, slipping easily through genres and tempos with subtle sleights of hand. A friend remarked that it was the first time in years he'd seen a DJ and thought: "What is he actuallyback there?" Or more specifically—how exactly did we get from that track to this one, and how is it that such a dramatic leap made sense?For many DJs, the answer might be vague and cloaked in mystique. For Hertz, it's likely to be quite straightforward, a result of specific methods he's happy to explain. Hertz is a passionate artist, something his productions and his DJ sets make clear, but he's also a hardcore pragmatist. For years he's worked as a DSP developer at Native Instruments, where he still holds a part-time role. He applies an engineer's logic to every aspect of his craft, from how to execute a transition, to the way he organizes his USBs, to his choice of which gigs to play. This has made him an extraordinarily capable DJ, with a record collection and mixing technique well beyond his years (at 29, he's been DJing for barely a decade). This mindset, combined with his ear for high-impact club records, has shaped a sound that's utterly his own.Ahead of his appearance at RA's party at RADION during ADE, Hertz told us some of the tricks of his trade.It depends what direction I want to go in. Going up is comparatively easy, you just find a high note to end on, go into something beatless and fairly intense, maybe do a couple of those in quick succession so it feels a bit more fluid, and then go into something faster.Maybe. Or layer a couple of them. It really depends on the track, but sometimes if you do it with only one, then it sounds a bit contrived somehow. Whereas if you bridge the gap with two ambient tracks, or layer them somehow, or do a bit more performative EQ work with them, then you can shape them in a way that works with the direction that you want to go in, tempo-wise and energy-wise. And obviously you have to pick the right track to start the new section and the right track to end the last section.I haven't quite perfected the formula for it yet, but I'm getting better at it for sure. It's important for me, because there's a lot of stuff at different tempos that I want to play, and I don't always want to spend 45 minutes ramping the tempo in between. Sometimes I want to go from 150 to 110 BPM, and there's no way of doing that without taking a few minutes in between to let people forget what tempo I was at before.A lot of it is gut instinct. A lot of it is thinking strategically about where I want the set to go. Sometimes those are the bits that are pre-planned. If there's a part of a set that I'll ever plan, then it's usually the transition points. Like, where do I want to get to at this time, and where do I want switch to, where do I want to get to from there, where do I want to finish?I've got a couple of useful playlists for that kinda stuff in Rekordbox. Like "Section Starters," "Section Finishers," stuff that ends on a beatless section, stuff that begins with a beatless section, maybe something that doesn't begin with a beatless section but starts emphatically enough that you can use it to start a new section with a new tempo. And then a whole load of beatless DJ tools, which I'm always on the lookout for. I don't spend that much time actively seeking them out, but a lot of it you just come across over the course of browsing for records.Yes and no. I mean, if it's a really long set, if I'm playing for three or more hours then I might do that. If I'm playing for two hours then maybe I wouldn't jump as far. Or maybe I wouldn't do any jumps at all. If I'm playing for two hours then I might play across like five or 10 BPM, or maybe not even change tempo that much, but I probably wouldn't have a 150 BPM electro section as well as a really slow section. Obviously, tempo is kind of the deciding factor in when and where I can play a lot of these tracks, because almost all of it is going to be beat-matched.Oh, I can say amore about how my USBs are organised. I mean, I don't know if it's interesting.I have pretty big USB sticks, like 128 GB. And I have two main folders: monthly playlists of new stuff, or stuff that I haven't played in a while that I want to make a point of playing, and then I have my kind of... I don't know what you call them, genre playlists, I guess. So in the first folder I have subfolders for every month, and every month I'll make a "Club" playlist, which is basically promos and new downloads from that month, and maybe some from the previous month. All of that will be between 110 and 135 BPM. Then I'll have a "Fast" playlist, which is clubby stuff between 135 and 160 BPM. I'll have an "Other" playlist, which is beatless stuff, and sometimes I'll have a "Slow" playlist, which is like 90 to 115. If I've got enough stuff from that month.It depends on the month. Typically the club playlist would be the big one, and it would have somewhere between 50 and 150, something like that.Each month, yeah. Not all new stuff. I mean, sometimes I'll have like 150 new tracks in a month, in which case I probably wouldn't include any of the stuff from the last month. But sometimes maybe I'll only have 50. And then the "Fast" playlist, I'll have maybe five, ten new things per month. Same with "Slow" and "Other." And then in the regular playlist folder, I have a techno subfolder, with a few different playlists: "Tracky Above 130 BPM" and "Tracky Below 130BPM." And all of the tracks in the tracky techno folder have a number from one to ten in the comment field, and that's basically their hardness factor. And then I sort it by hardness, which is really useful. Then there are the utilitarian, transition-oriented folders: "Section Closers," "Section Starters," "Beatless Transition Tools," and an "Empty Club" playlist, which is music I would play when doors open. What else... "Fast And Functional" is a big one. And I recently made a playlist called "Urgent Wee," which is tracks that are all more than ten minutes long for when you really gotta go.What else... "Slow And Functional," which is still pretty thin on the ground, but it's getting there. That's the 60 - 90 BPM range.It is, but it's really fun as well. Something i'm striving for over the next few years is being able to play a full-length set at any tempo between 70 and 150 BPM.I don't know, I was noticing that as well. It sounds like I'm really preoccupied with tempo, but I'm not really. It's more that, when you're talking about playing beat-matched sets, then the tempo is critical to whether or not you can play something in a certain context or not. And it's also that I'm getting better at—or my record collection is getting better at—playing to a certain energy level with a degree of freedom from tempo, rather than using tempo to make something more energetic or less energetic.Yeah, I don't know. I guess what it comes down to is a desire to be able to play to the fullest possible extent using other people's music. And tempo is one axis—like, one axis in the overall multi-dimensional space of music. Energy level is another. There's a lot of different melodic components that factor in as well, like density and sparsity. All of these things are directions that you can go in from a certain point. And it's really useful to me to have my music sorted in such a way that I can start from a certain point, and go in an incremental direction from there, or switch to something completely different via some tool.I mean, I have a lot of tricks that I use again and again, sure. I can't really scratch but I have a few basic things I like to do.OK, yeah, but I can't do the crossfader shit, I just cue up the first beat and make somenoises from time to time. I guess I use mixing trickery as a way to create momentum where momentum isn't forthcoming. I see EQ'ing and mixing as compositional tools as much as anything else, and in the overall layout of a DJ set I feel like it really helps to kind of define the way in which you're trying to combine two different things. I don't really subscribe to this idea that DJing should be just about playlisting one track after another and letting the music speak for itself. I mean, I have the utmost respect for people who can mix that way, but that's not really what I'm about.Let's see. Cutting in individual beats with the crossfader, that's a big one. You know, punching in the snare so it feels like you've brought in an instrument, rather than a whole track. Using the filters and the EQ in combination, knowing exactly what the frequency response of each of them is and how they interact. That's something that's really important to me.In my day job, several years ago, one task that I was asked to do was to write a report on the EQ and filter curves of a lot of industry standard mixers, including the [Pioneer] DJM-800/900, [Allen & Heath] X:ONE 92, and one of the Rane mixers of the time, which was actually tremendously helpful for me, because for the first time I could actually visualize the curves on all of those EQs. And they vary immensely, they're really, really different. It made me think a lot about—OK, I'm going on a slight tangent here, but it gave me a lot of insight into why some people think certain mixers sound good or sound bad, and that a lot of the time it's not necessarily to do with the in-to-out signal path, but what exactly the EQs are doing—whether when you cut the bass it's cutting stuff that makes musical sense to cut, or sounds good on a big system or whatever.The upshot of that is knowing graphically what the frequency response of a X:ONE 92 EQ and filter looks like, in combination with having one at home and being able to experiment to my heart's content. I know that frequency response by heart, so if I want to bring in a track in a certain way, I'm not guessing where the EQ should be or where the filter should be, I know exactly what to do in order to just get the sizzle of a hi-hat, or just get the body of a snare or whatever. Or whether it's possible on certain mixers to do certain things, like turn down the mids and the highs so that you only get the bass, and then bring in the hi-hats from the other track as a kind of shock tactic. Which you can do, for example, on the isolators on the DJM-900, but not on a X:ONE 92, unless you use the low-pass filter, but then you're doing it with a filter and not with the EQ.So, long story short I guess creative and extreme use of EQ'ing is another trick. Also, I do a lot of stopping the platter, rather than putting the fader back.Yeah.Well, I have a tendency to do more spinbacks than I should, which is a bad habit. One or two in a set is OK, but five or six is a bit much. Stopping the platter is a lot more subtle than a spinback. Sometimes you don't even notice it, but if you do it in the right place—if you pull out the bass on the other channel first, and then bring it back in when you stop the record, and you do it with the right combination of records, then it gives you a much more definitive transition, much more than if you just pull the fader down.No, because you've got thewhereas if you just cut the bass and pull the fader down at the same time as bringing the bass back in, then it's just gone, and sometimes you're left with this kind of hole.What else... tricks, tricks, tricks... Playing the EQ rhythmically, you know,with the highs. You can make it a lot more dynamic. If you do it musically enough, it can make the difference between a mix that sounds really static and boring, and one where you've kind of propelled forward to the next track. A lot of these are old Detroit tricks, which I apply more or less tastefully depending on how I'm feeling.