Archive for February, 2016


Sample Manipulation 3

In an earlier post in this series I passed comment on the program ‘REplay PLAYer’, mentioning its creator, Karlheinz Essl, and describing it as ‘ a multi-featured program for manipulating a single sound sample’.

I was talking in that post about programs suitable for manipulating a group of four short samples, so I didn’t go into ‘REplay PLAYer’ in more detail.  However, I thought it would be worth adding a post on programs for manipulating a single longer sample.

‘REplay PLAYer’ is my favourite of these – it costs a bit to buy it, but I’ve found it very useful in the past, and it has a couple of features which make it particularly versatile in use.

It’s described on its webpage,, as a ‘generative sound file shredder . . . based on the paradigms of granular synthesis. The program de-constructs a given sound file and re-composes it by using realtime composition algorithms [and] can be used as a tool to generate an infinite and every-changing sonic stream from a single sound file for artistical, compositional or mere recreational purposes. It can also be regarded as a computer based instrument for live performances, as an interactive sound installation or a generator for ambient music.’

The following screenshot indicates some of the program’s important features:

REplay PLAYer1

First of all, the sound file of your choice can be imported into the program, via the ‘Shredder’ menu, and settings can be adjusted affecting changes to the samples’ volume, pitch, EQ, panning and stereo spread which are automatically made, tailoring the way in which the file is ‘shredded’.

Better still, three of your favourite VST or Audio Unit plug-ins can be imported and used alongside the built-in effects – the picture shows two that I often use, brainworx bs_solo (Stereo imaging) and GSi TimeVerb (Reverb).

In this way you can allow your sample to run while small or large changes are made to it.  At any time you can change, for example, the range of pitch, volume or panning variations, turn them off or set them to move randomly from one value to another.

In addition to this, what makes ‘REplay PLAYer’ – as described – a ‘computer based instrument for live performances’ is the ability to control a number of the parameters in real time via MIDI.

I didn’t feel I needed to control all the possible features, but programmed my trusty Korg NanoKontrol to alter Volume, EQ, crossfade, glissando (i.e. pitch) and the amount of signal sent to the three plug-ins.  All knobs and sliders had to be set to CC#7; the following parameters could be set by assigning the knobs and sliders to the following MIDI channels:

Channel 1: granularity
Channel 2: density
Channel 3: glissando
Channel 4: minimum pitch
Channel 5: maximum pitch
Channel 6: crossfade between original and shredded sound
Channel 7: volume range
Channel 8: mix into plug-in 1
Channel 9: mix into plug-in 2
Channel 10: mix into plug-in 3
Channel 11: EQ low
Channel 12: EQ mid
Channel 13: EQ high
Channel 14: panning
Channel 15: spread

As the Menu suggests, ‘REplay PLAYer’ will also record the results of its work to a file (aiff, ulaw, wav or raw data) on your hard drive.  It’s important to note that the program is set to start or stop working in the ‘Shredder’ menu, and recording is set to start or stop separately in the ‘Record’ menu; audio is turned on or off in the ‘Audio Status’ window.

This is a recent track created using REplay PLAYer, and a picture of  my set-up in action:



Another program I’ve used on occasions for manipulation of a single file is ‘Metamix’.  This program gives the user less control than ‘REplay PLAYer’ – a deliberate choice on the part of the designer, Jason Freeman – but works well with some sound files.

As described here:, the way ‘Metamix’ works is that a ‘simple generative process remixes an audio track, using an infinite integer sequence to reorder and layer chunks of the original audio . . . The program includes twelve such sequences, chosen from Sloane’s exhaustive collection, The On-Line Encylopedia of Integer Sequences.’

These three screenshots of ‘Metamix’s control windows shows the elements you can choose – the twelve number sequences are given names, as can be seen, such as ‘Wide Exponential Slow’, ‘Up and Down’ and (my favourite) ‘Joy Ride’.


As the document above explains, ‘To remix the audio track based on an integer sequence, the software first marks the audio track at equal-length time intervals and labels those markers with the natural numbers. Each time it obtains the next number in the integer sequence, it begins audio playback at the correspondingly-numbered marker.

‘When a new number from the integer sequence triggers audio playback at a marker, one or more previous layers of audio playback may continue uninterrupted. This layering renders the discrete generative process in a smoother, more fluid manner. To further this effect, MetaMix also gradually fades each playback layer in and out over the course of its lifespan, creating gradual crossfades between old and new playback layers.’

In other words, ‘Metamix’ can create quite a dense sound, with short, overlapping sequences, or a more spacious sound with longer extracts from the original source file.

The following example is typical of the way I’ve used Metamix.  At the beginning is a short extract from an existing piece, beginning with assembled street sounds and continuing with a repeating marimba theme.  Other instruments were omitted from the old piece in creating the new one.  This is followed by an extract from the new piece, after the old one has been worked on by Metamix:


I haven’t yet attempted to produce a Pure Data patch which will work on a single file in these ways.  If I do, you can be sure I’ll be writing about it here!


February 2016

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