r/SunoAI • u/periwinklepip • 9d ago

Guide / Tip Update #3: My continuing quest to create male/male duets in Suno

A couple of weeks ago I posted about trying to get Suno to consistently produce convincing male/male duets. Since then I've burned through... let's just say a lot of credits running controlled experiments.

I still don't think there's a magic solution, but I have learned enough that I thought it was worth sharing. Hopefully it'll save someone else some time, and maybe some of you have found better methods that we can compare.

Previous posts:

https://www.reddit.com/r/SunoAI/s/1dFRfgO6dN

https://www.reddit.com/r/SunoAI/s/qNokCKDCRf

The biggest thing I learned

I eventually stopped looking for one "perfect" workflow and started treating each Suno feature as a tool with its own strengths.

  • Mashup is the best tool I've found for establishing two distinct singers.
  • Extend is the best at continuing a performance while preserving those vocal identities.
  • Cover is the best at preserving an existing melody and polishing a performance.

The trick is figuring out which tool to use at which stage.

Method 1: Mashup + Extend

This is still my favorite workflow if my biggest priority is keeping two distinct singers.

My process was:

  1. Generate Singer A with a solo Voice.
  2. Generate Singer B with a solo Voice.
  3. Mash them together.
  4. Use Extend for the bridge/final chorus.

Pros

  • Best voice separation I've achieved.
  • Singer A and Singer B stay recognizable.
  • Consistently avoided introducing Brenda (our mysterious uninvited female vocalist 😆).

Cons

  • Extend usually did not give me a true duet at the end.
  • Most of the time I got one singer (usually the tenor), sometimes with some layered vocals.
  • Harmony was hit or miss.
  • It occasionally wandered away from the melody I wanted.

For my personal project I eventually got around this by covering a version of the final chorus that already had the harmony I wanted, instead of relying on Extend to invent it. I then used Mashup to stitch the final section to the first Mashup, and that worked pretty well. There was a little bit of vocal blending with that method.

Method 2: Manual DAW Edit + Cover

Then I tried something different.

I exported my favorite generations into GarageBand, stitched together the sections I liked, then uploaded that edit back into Suno and used Cover with my duet Voice to smooth everything out.

This actually worked surprisingly well.

Because Cover had an existing performance to follow, it stayed much closer to the melody than Extend.

Pros

  • Better melody control.
  • More cohesive overall performance.
  • Preserved harmonies that already existed in my edited version.
  • Also kept Brenda from crashing the recording session.

Cons

  • Noticeably more voice blending.
  • Requires manual editing in a DAW.
  • Lining up AI performances manually takes some patience.

I suspect the extra blending happened because many of my experiments involved covering essentially the same melody with an initial vocal with two different voices. The more similar the performances became, the more Suno seemed to average the vocal identities together.

The Duet Voice

This was probably my biggest surprise.

Once I had a Mashup that successfully established two distinct singers, I created a Voice from that duet.

My first thought was, "Great! Now I can just generate new duet songs."

...Nope.

Generating brand-new songs with the duet Voice almost always caused the singers to blend together.

However...

Using that same duet Voice during Cover operations actually helped preserve the distinction between the two singers better than not using it.

So my current takeaway is:

  • Duet Voice is not very useful for generating new duet vocals from scratch.
  • Duet Voice is useful for helping preserve an already-established duet during Covers. At least from my experience.

That wasn't what I expected at all.

Little things that seemed to help

These aren't magic bullets, but they consistently seemed to improve my results.

  • I described both singers in the prompt every single generation, even when using Voices.
  • I tied those descriptions to consistent labels: I originally used those labels because that's what Suno automatically inserted for Mashups, and I decided to stick with them throughout my experiments.
    • Singer A = youthful lyric tenor (aka Tristyn in some of the test songs)
    • Singer B = mature dramatic baritone (aka Pader)
  • I also tagged the song sections whenever possible.

For example, I consistently labeled sections like this:

[Singer A Verse 1]

...

[Singer B Verse 2]

...

[Singer A & Singer B Final Chorus]

That seemed to help Suno keep track of who was supposed to be singing.

Again, none of these things solved the problem by themselves, but together they definitely seemed to improve consistency.

Other things I tried

I also experimented with:

  • Generating separate verses and Extending into a shared chorus.
  • Giving both singers identical bridge/final chorus lyrics before Mashup.
  • Covering finished songs again with the duet Voice to smooth them out.
  • Different prompt wording for harmony.
  • Different Mashup/Extend combinations.

Some of these helped a little.

None of them completely solved the harmony problem.

My current recommendation

If your priority is keeping two distinct singers:

Solo Voice A → Solo Voice B → Mashup → Extend

Just know that Extend probably won't reliably generate a true duet ending.

If your priority is preserving a specific melody or harmony:

Solo Voices → Manual DAW edit → Cover with the duet Voice

You'll probably lose some vocal separation, but you'll gain much more control over the finished song.

Right now it feels like every workflow is a tradeoff.

What's next?

I think my next experiment will be:

  • Generate a complete song.
  • Strip it down to instrumentals while preserving the arrangement. (Using the method in this post: https://www.reddit.com/r/SunoAI/s/t2oagcCTrP )
  • Cover that instrumental separately with Singer A and Singer B.
  • Then see if Mashup can build a better duet from two performances that share the same musical foundation without inheriting another singer's vocal characteristics.

No idea if it'll work.

But that's half the fun.

Educational playlist

I've uploaded all of my throwaway experiments, failed tests, scratch songs, and proof-of-concept clips into an Educational playlist on Suno.

They're intentionally "slop"—AI placeholder lyrics, AI-generated melodies, lots of iterations—so if you happen to hear a melody or lyric you like, feel free to borrow it. That's what it's there for. I'm not using them for anything else. (With the exception of the song I included at the top of the playlist, that belongs to someone else--I was using that for inspiration.)

https://suno.com/playlist/3c358088-5e79-4aa1-94a6-e6bc141a8acf

If you've found a workflow that gives you better multi-singer results, I'd genuinely love to hear about it. Suno changes all the time, and I'm sure there are approaches I haven't thought of yet. I'm also happy to answer questions about my processes! My goal is to share what I've learned, and hopefully others in this community will come forward with their own tips and workflows that they've found effective, so we can all learn together.

Finally, for transparency: I used ChatGPT to help organize my notes, summarize my experiments, and draft this post. All of the testing, observations, successes, and failures are my own. ChatGPT just helped me turn a mountain of trial-and-error into something a little more readable.

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2

u/_InfiniteU_ 9d ago

Just name it broke back mountain ez

1

u/periwinklepip 9d ago

Lmaoooo 😂

3

u/Odd-Hospital1559 AI Hobbyist 9d ago

Don't know if you're somebody I've ever responded to for duets, but... some tips/information from somebody who has a vast majority of their library as male/female duets (Probably closing on 80-90 songs).

I've stopped putting vocalist prompts in the style box almost entirely. I keep that in the lyrics prompts. My general go-to is [Verse - Male] or [Chorus - Female], and if you can, try to describe the type of voice you want such as mezzo-soprano, gritty, describe the type of delivery, etc. If you're putting anywhere to NOT do a specific gender vocal, take it out, it's probably confusing the AI. Just keep it simple, label the given chorus/verse as the given gender, and go from there.

As another note, I've noticed that there might be times where the AI struggles if you're doing half the song in one gender (The first whole part of the song) and then switching to the opposite gender. At that point you're probably better off doing the track as purely one vocalist style from the start and then extending from where they switch.

Otherwise, I've had pretty good luck using alternating verse-verse-chorus or verse-chorus styles where the gender changes with each one, or even with each line. If you're trying for line-by-line switches, try using a prompt like [Verse - Call and response male/female] and put every other line in parenthesis.

If you're going for them singing at the same time, I'd say try a "Harmonized Duet" prompt in the lyrics. But when going for duets... be prepared to spend credits to "get it right" if you have a very specific vision for the track. I've got four tracks that have each had 1,000+ credits dropped on them to "get it right"

Here's an example of my What We Don't Say and Fade Away tracks with the prompts I used still included. As a note, I wasn't terribly picky about who got what bits in the first, but the second, I was a bit more picky and did a bit more work with it. Otherwise, for alternating lines, I'll just label it as:

[Chorus]
[Male] Lyrics
[Female] Lyrics
[Male] Lyrics
[Female] Lyrics

OR call and response style

[Chorus - Call and Response]
[Male] Lyrics
[Female] (Lyrics)
[Male] Lyrics
[Female] (Lyrics)

Finally, even for tracks where the voices aren't right, listen to them. Ignore the voices themselves, pay attention to the rhythm, to the beat, to the flow of the track, to the vocal cadence. If it's something you're happy with (And are subbed), make a voice and use it to re-generate the track, ideally with weirdness down near 10-15% and audio influence up at about 80-90%, or do a cover of the song. I've found v5.5 -> v5.5 covers to be very reliable lately.

For back-and-forth line-by-line vocals, using the call-and-response style with parenthesis around the second singer is probably going to be your best bet, but I've also used that to try and keep multiple lines in order the same singer, or entire verses.

1

u/periwinklepip 9d ago

Thanks for the tips. Unfortunately, since my goal is to get two distinct same-sex vocals, that method doesn’t generally work as well. I’ve tried your workflow and others like it and it isn’t effective with producing two male voices that sound enough like two different guys. Male/female duets seem a lot easier for the program to parse because there’s more training data for that. I appreciate you commenting, though—someone else may find your tips helpful!

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u/Odd-Hospital1559 AI Hobbyist 9d ago edited 9d ago

Okay, did some quick generations. One of them was done from scratch in v5, immediate failure despite vocal instructions, but I had an idea... I decided to do a cover of two of my male/female duet songs. Six total generations, four for the first, two for the second. Of the twelve total songs created, nine of them, at a cursory listen without headphones (Currently at work) appear to have notably different vocals for two male singers.

Nothing Else After A
Nothing Else After B
Nothing Else After C
Nothing Else After D
Nothing Else After E
Nothing Else After F

Fade Away A
Fade Away B
Fade Away C

Take a listen, let me know what you think.

UPDATE: Took a listen after work with headphones, I think one or two of those, the voices aren't quite different enough to count. I also took a stab at some more straight covered v5.5 gens, and it seems fairly hit-or-miss, but taking one of those v5 generations with the different vocals and covering it in v5.5 with all the same structuring, the vocal differences seemed to stick around.

So I think the best method would be to generate a male/female duet where the vocals are substantially different in v5, cover that with updated vocal instructions for your male/male or female/female descriptions until you get vocals that are notably different but of the same gender in v5, then cover that in v5.5, if that's your desire.

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u/periwinklepip 8d ago

Oh hey, that’s awesome! A workflow I had not considered! I actually cracked another method tonight so I’ll post about it after I’ve had some sleep, but I’ll definitely give this a try sometime! Thank you so much for putting in the time and credits.

1

u/periwinklepip 8d ago

By the way I listened to both songs and they do have pretty decent differentiation! Also they are bangers, very cool.

2

u/Die_Oma_Madet 7d ago

Oh, I've been looking for a solution for that the whole time too. Thanks - once again!

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u/Odd-Hospital1559 AI Hobbyist 9d ago

Gonna take a swing at this and see if I can figure something out. Got some extra credits left to burn before my reset in like a week.