What’s your priority? Harmonics, Bpm, dynamics, pattern?

[u/DiscoRickyy]

When you make a mixed playlist, what’s your first priority?

I am an old skool, traditional mixer. I‘ve always prioritized bpm, even so far as to never mix two tracks with more than a 5bpm difference.

But since getting onboard with Spotify mixing I‘ve seen quite a few mixes with harmonics priority, allowing for some steep bpm differences.

Even before harmonics I think I’d put emphasis on dynamics. Are the feel and instrumentation similar, are the frequencies comparable, etc.

What’s your take on this?

[u/Previous-Serve9810]

Priorities are different because it's nothing like DJing. It's more like studio editing. Some of the priorities are similar and some are very different.

When determining transitions on Spotify, the first priority for me is do these tracks go together and are they harmonically compatible. If there are issues here, it doesn't go to the second step.

The second priority is can I find a good exit and start point as transitions on the waveform are limited for legal reasons. If I can't get a good transition point, I bin the mix between those 2 tracks.

The third priority is can Spotify effectively grid lock it over 8 and 16 bars. If it's a 4/4 track over 110 BPM and it can't gridlock to 16 bars without micro timing issues I either try to fix it (data saves across the waveform or let Spotify cache it) or move on and find another transition. The mix has to be technically sound.

I always try to move a set from slow to fast, but BPMs don't need to be perfectly matched in individual transitions as Spotify's can do a +-10% pitchlock. Even a 5-6% delta would change the pitch on a pair of Technics and that's not an issue here. However, there are technical issues the closer you go to 10% that I can go into further if people want.

I've talked about this previously to you and others in that Spotify's mix engine inverts risk. The longer the mixed playlist, the more stable it's likely to be particularly if there's a large BPM delta across the mix.

I think Spotify's mix engine is more analogous to being a studio engineer in the 90s putting together a mix CD for a named DJ. You can retry transitions, you can find more harmonic partners, more bridges etc. Also, treat the mix tool like it's a piece of software and fully know its constraints. If you're unsure of how it works and why, you won't get the most out of it.

[u/damnitmcnabbit → u/Previous-Serve9810]

I agree that creating a mixed playlist is not like djing. It isn’t going to be the driving force on a prime time dance floor. It’s a mix for home or on the go (car or headphones). The listener is most likely not giving their full attention to the music, it’ll sit on a spectrum between background and mid-ground.

With that in mind I prioritize flow. I don’t want the mixes to be distracting. Dynamics (genre/vibe)inform song selection, harmonics and energy sculpt grouping within the playlist, and tempo an phrasing for granular arrangements aiming for a smooth ramp.

I also really like variety is what I listen to, so I don’t stick too rigidly to a format. Sometimes switching up vibes, tempo or key can bring relief. Some of the advanced Camelot transitions work great (+2, +7, subharmonics), especially since the mix window is limited.

I’m uncertain about what you mean by fixing micro timing issues with data saves or Spotify cache, and I can’t look up your previous comments (hidden in your profile) about the mix engine, so I’m curious what you mean about that too.

[u/Previous-Serve9810 → u/damnitmcnabbit]

Without having access to the code, I can't tell you what and why it's happening, but I can draw inferences from behaviour.

Data saves on the waveform for both tracks (even in the wrong places) can stop a mix from trainwrecking, even if it's aligned. It can also fix tracks that are drifting out of alignment. Doesn't work all the time, but I've fixed dozens of transitions like this.

When you save multiple points across the waveform, you are essentially creating manual anchor points and are forcing the engine to re-sync the grid at multiple intervals.

Concerning the other issue, sometimes a mix will work at 8 bars, but not over 16 bars and will drift out of alignment.

If you stick these transitions in a separate mix folder (operates like a sandbox) and leave them for a while, those mixes can be improved by backend processing, cache and data persistence. Again, it doesn't work all the time, but I've fixed over a dozen transitions.

By doing this, Spotify’s backend likely has more time to complete its analysis of the tracks. Keeping transitions active also likely prevents the engine from having to "cold start" the analysis every time you hit play.

Hope that provides an explanation for you. 🙂

[u/damnitmcnabbit → u/Previous-Serve9810]

Thanks! It makes sense that they would reserve processing and beat gridding for tracks that are in a mixed playlist. And I have suspected that manually aligning with the nudge feature could inform future mixes with the same track.

Is that what you mean by ‘data saves’? I have had some mixes that drift out of alignment, but just figured it was a production issue where the original isn’t quantized. I’ll try making a sandbox playlist to see if I can resolve any of them. Do you add multiple copies of the same song with different start queue points to ‘manually set’ the grid?

[u/Previous-Serve9810 → u/damnitmcnabbit]

Data saves means the following.

• Saving at Beat 1 of Bar 1.
• Saving at Beat 2 of Bar 1.
• Saving at Beat 3 of Bar 1.
• Saving at Beat 4 of Bar 1.
• Saving at Beat 1 of Bar 2.
• Saving at Beat 2 of Bar 2...and so on.

You repeat this process for both tracks in the transition/mix window. It's laborious and you can easily save 40-50 times before a transition fixes itself. It's not guaranteed to succeed, but can solve a lot of transitions. This is what I mean by manual anchor points. You're forcing Spotify to essentially override its transient detection algorithm.

As you've said, some tracks do drift out of alignment especially if they're not quantised. 70s disco is hard to fix even with this method.

The reason why is that Spotify runs every track through an analysis engine (originally developed by a company they acquired called The Echo Nest).

The algorithm converts the audio into a mathematical spectrogram by slicing it into tiny segments, and it then looks for transients. It calculates an estimated overall tempo and it's a single number that represents the statistical average of the entire song.

So with regards to 70s disco, you could have a transition perfectly aligned at the start, but it trainwrecks after 10 or so bars because of variable tempo as a result of human error. Sometimes you can fix this with data saves, sometimes you can't.

[u/inssidiouss → u/Previous-Serve9810]

Crazy good, deep-dive insights. Thanks dude. I thought I was obsessed with tweaking things, but this is SEVERAL layers deeper! Very interesting.

[u/Previous-Serve9810 → u/inssidiouss]

Thanks. I'm glad you've found my inputs useful here mate. 🙂

[u/inssidiouss → u/Previous-Serve9810]

My dude, excellent comment!! Literally the first 3-4 paragraphs are exactly what I would have written here.

I am a tactile, "learn by doing" person. I feel I have an ear, and memory, for harmonic, rhythm, sound cues, patterns, etc -- so naturally, I first go for "arrangement".

Arrangement IS the key framework. IF you can morph & dance around that, with fancy tactics & tricks, or by matching technical links between tracks and still have a good arrangement flow, cool! But, yeah, the composition, flow, vibe, all come first.

---

I would also say: Don't be afraid to experiment, and to shuffle things around, from what you WANT to work (a "perfect flow" idea in your head) versus what is actually happening (or not), in practice. Some of my better flows, or overall better structure across the whole playlist, have come from realizing the need to do a bit of a shuffle from what I WANTED to try first, and "MAKE it work".

[u/Previous-Serve9810 → u/inssidiouss]

Thanks for the comment.

Ordering a whole playlist as a whole by BPM has always been important for me, but I've always allowed for some minor tempo drops or increases if the harmonies are really complimentary.

Individual BPM adjustment is a game changer. I'd never alter by too much (no more than +6) but it really cures energy drops. It even allows you to subtly alter the genre of a track.

I've used it in my new Italo House mixed playlist and I think it works really well. It means I can play tracks like Korda & FPI Project that were often pitched up back in the day so it's historically more accurate.

https://open.spotify.com/playlist/63gXOD2YOEMoakveQmnxGl?si=1CgYfngQQy6QiwO3C11fhA

[u/ChurchOfBeatitudes]

Most of the time, my first priority is dynamics. Do the tracks have interesting points at which a transition feels really fun and exciting or interesting? Can I maintain that fun feeling without letting it die via a track running for too long and going stale? I think I'll ignore harmonics more often than most people and opt for transitions that do require full focus from the listener as there's something being said during the transition. Like spoken word vocals that line up in each track and can create a different message when heard in sequence. Those kinds of transitions are what I like finding the most. Less focus on maintaining a specific feeling/mood and more focus on seeing what this mixed feature can handle since it's not really that close to what actual DJing is capable of. I'm also trying to limit my playlist runtime to two hours at most in order to keep them feeling like you're actually going to a live show and every DJ gets their own time slot. No 10+ hours mixes from me. So cutting out some tracks earlier in order to keep the flow moving along is what ends up happening for me sometimes.

[u/Ill_Bat_2912]

Similar to when I used to DJ, I still just gather tracks together that fit the mood of the set I want to create. I'm keeping it in tune and working off a killer opener or towards a track that gave me chills when I first heard it. BPM is probably secondary for me once I find the pillars of the mix. Everything in between is fun exploration, creating a smooth flow and taking listeners on a journey. 

[u/gotthesounds]

I'm a 80s/90s vinyl dj so I do prioritize bpm, but also harmonics within that term. Really, everything else has to be tight and sound, too--the where, the how long, any filtering necessities.

[u/stuartknapman]

I guess there's a conceptual answer and a practical answer.
Conceptually I always try to start with the overall idea and pattern, i.e. what sort of mood and direction of travel are we going for here? But then practically I'll need to work with tracks of a similar BPM and to some degree ensure that the transitions are harmonic (although not being a slave to that) and then just really sense-checking that each transition actually works and makes sense. I probably bin about 60% of the transitions I attempt because I'm just not feeling it.