Not sure where to put this, so I figured this section would be the best place to post.

I want to try to make an audio visualizer, but I have no idea how to get Scratch to detect music I put in and actually visualize it, help please?

I'm not sure it's possible: there aren't any blocks that let you detect sound frequency etc. (all it has is volume).
Realistically all you can do is either pre-make it for a certain set of sounds or just put in random pretty colours.

You can do it as follows.
You need speakers and a microphone for this to work! (a webcam on your device is fine).

Write a project that plays the song / music using the block

play sound [ v]

Once the song starts have a loop in your project that samples the loudness of the music using the loudness block and then draws a simple representation of the loudness on the stage.
eg. if your song is 95 seconds long

reset timer
repeat until <(timer) > [95]>
clear
go to x: (0) y: (0)
pen down
move (loudness) steps
end

Check that this is working ie. the visualizer reacts to the sound


Now create a list “Song Loudness”
Inside the loop above put

add (loudness) to [Song Loudness v]

After running the project the list will have all the song loudnesses stored in it.
Remove the line

add (loudness) to [Song Loudness v]

as you don't want to damage the list.

Now you can rewrite the project replacing

reset timer
repeat until <(timer) > [95]>
end

with

set [n v] to [1]
repeat until <(n) > (length of [Song Loudness v] :: list)>
change [n v] by (1)
end

and rather than using “loudness” for your visualizer, use:

(item (n) of [Song Loudness v] :: list)

The project can now be run using your recorded loudness values in the list.

I did exactly this in my project Sound Visualizer a la Minion: https://scratch.mit.edu/projects/179187908/ which uses a list of loudnesses if a microphone is not detected.

here's an example of a volume-based display: https://scratch.mit.edu/projects/157976976/

you could build on that to do your own visualisation

Scratch doesn't have any waveform-analyzing functionality, so making a true audio visualizer is not possible. However, you can look at your song's waveform in another program and based on that information animate something in Scratch.

As others above have pointed out, there's no way for Scratch to analyze wavelengths. You can, however, use the

(loudness)

block to simulate wavelengths via microphone. If you want to see how this is done, check out the Audio Visualizer studio (I'm not going to link it for you because it's featured on the front page)

For challenge sake, you can make music and you may be able to base visuals off of other variables. Note, tempo, instrument, volume what you can control on scratch. Many people make midi type things or something more randomized so as not to have to code out whole songs note by note. Then you'll have more info to base your visualizer on.

1. I'd thought about making something like a non scratch thing I saw that scans a table each second set up with various shapes at certain physical heights. Not sure of specifics but higher on y is higher pitch from left to right is the timing and certain shapes may mean things or sustain a note and use a camera to project the actual table into scratch in real time. Thats different but just throwing it out there.

Okay, I get it!

Okay, how do you make a sprites mouth move when you say some thing?

Jimmyjangy wrote:

Okay, how do you make a sprites mouth move when you say some thing?

don't necropost or hijack

I'm trying to do this on one of my projects, but i want it to react to audio I'm playing inside the project! How in the world to I do that?

Jimmyjangy wrote:

Okay, how do you make a sprites mouth move when you say some thing?

Look at these!
https://scratch.mit.edu/projects/207648736/
https://scratch.mit.edu/projects/190402666/

It would be cool if Scratch 3.0 had a sound-length tracker of some sort.

Yeah I wish 3.0 did ):

i want it to viualize the song much like this one https://scratch.mit.edu/projects/181307508

Hello! I have found the MOST SIMPLE way to make a visualizer! It takes these:

say [
when green flag clicked] for (2) secs
\
when green flag clicked
forever
change size by (loudness)
set size to (100) %

Well, that makes sense