Is there a plugin to morph a sound into another?

[DefNotKyerix]

I'm trying to make an effect where one instrument morphs into another. I've tried the crossfade effect, but that only controls volume. I want the first instrument to start changing in pitch and form to gradually morph into the second instrument. This effect can be seen in Bummerland by AJR (https://youtu.be/7Kuwwta_Mms?t=128) and Way Less Sad by AJR (https://youtu.be/VlVhUbGa2pg?t=192) Is there a plugin or way that I could achieve this effect of one instrument morphing into another like how they did?

[Trebor]

pitch-tracking (or AI) required to morph voice into an instrument.
There is a free option ... https://youtu.be/bXBliLjImio?t=191

[jademan]

I've tried the crossfade effect, but that only controls volume.

How is that? If you have two synchronized recordings of two different instruments, then crossfade should do the morphing, by gradually reducing the volume of the first and increasing the volume of the second resulting in a morph.

[steve]

If you have two synchronized recordings of two different instruments, then crossfade should do the morphing, by gradually reducing the volume of the first and increasing the volume of the second resulting in a morph.

Crossfading is different from "morphing":
Consider a 440 Hz tone crossfading with a 1000 Hz tone - that's "crossfade".
Consider a 440 Hz tone gliding up to 1000 Hz (like the "Chirp" generator) - that's "morphing"

Morphing is much more difficult to perform than crossfading, and Audacity does not have a "Morph" effect.
Typically morphing is done by interpolating the FFT spectrum from one sound to another (along with interpolating the amplitude). It is probably "possible" to create a morphing effect with Nyquist, but that would be a very "advanced" project, requiring thorough knowledge of Nyquist programming, FFT manipulation, and a lot of development time.

[Trebor]

Here's an example using the tone-transfer* website I alluded to above ...

Koz-Violin tone-transfer.flac

(1.22 MiB) Downloaded 13 times

[ * it's a PITA: only 15 seconds of audio, minutes to process, only 4 instruments, of which only 1 or 2 are useable ].