# Playing a song and accessing its spectrum data

**URL:** <https://qa.fmod.com/t/playing-a-song-and-accessing-its-spectrum-data/12212>\
**Category:** Unreal Engine\
**Created:** [December 21, 2015, 3:01am UTC](https://qa.fmod.com/t/playing-a-song-and-accessing-its-spectrum-data/12212 "2015-12-21T03:01:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Weaver](https://avatars.discourse-cdn.com/v4/letter/w/3d9bf3/32.png) [@Weaver](https://qa.fmod.com/u/Weaver)\
**Post date:** [December 21, 2015, 3:01am UTC](https://qa.fmod.com/t/playing-a-song-and-accessing-its-spectrum-data/12212/1 "2015-12-21T03:01:12Z")

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Hi guys, I know this is an incredibly noobish question so I hope you’re patient with me - I just cannot find the resources on this.

I am using UE4 and I have the fmod plugin installed.  
Ideally using blueprints, I wanted to play a song using the FMOD plugin (not 3d positional or anything) and access its spectrum data as it’s playing.

I remember many years ago (2010) FMOD could run an FFT over the audio playing with a given window size and this information was available in the C++ library back then - but I simply cannot find a way to make this happen in UE4s blueprints. Do I need to use FMOD Ex for this?

Any help would be very, very, very appreciated 🙂

Thank you!

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**Author:** ![brett](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/brett/32/261_2.png) [@brett](https://qa.fmod.com/u/brett)\
**Post date:** [December 21, 2015, 9:59am UTC](https://qa.fmod.com/t/playing-a-song-and-accessing-its-spectrum-data/12212/2 "2015-12-21T09:59:56Z")

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If you using the low level API and System::createDSP, you can create a DSP with the FMOD\_DSP\_TYPE\_FFT type, and add it with ChannelGroup::addDSP command (a channelgroup can be retrieved from an eventinstance or a businstance) You can then grab the spectrum of a bus using DSP::getParameterData