ambient soundscape generator
© 1998-2013 by Karlheinz Essl

Universal Binary   vs. 4.0
released: 11 May 2013    NEW

I believe this is an excellent piece of software. fLOW allows the user to create awesome ambient pieces in minutes. As one may hear quite often, the source material makes the difference in how you will like this software. The $20 is not that hefty for all the interesting sound that this software has produced.

MacUpdate - 10 Sep 2004:

Basics | Download | Listen | License | Reviews


fLOW is an audio computer program running on Apple Macintosh machines. It generates an ever-changing and never repeating soundscape in real time that fills the space with flooding sounds that resemble - metaphorically - the timbres of water, fire, earth, and air. This ambient soundscape generator adjusts itself through various parameters and controllers that are represented in real time on your screen.

Feed your own sounds into the system and listen what the algorithms are composing. The system parameters can be accessed either by the mouse or with an attached MIDI controller. Use your own VST or AU plugIns for extended sound processing. And finally, the result can be recorded as a sound file.

Originally, this soundscape formed the basis of the site-specific performance work-in-progress fLOW that was carried out in numerous steps and took place in various location with changing musicians from different fields like New Music, experimental jazz, free improvisation and New Electronic Music.

User interface of fLOW 4.0

User interface of fLOW 4.0

What's new in version 4.0?

System Requirements


fLOW is released as shareware. Please register your copy to ensure the further development of this program. You can purchase a registration code for $ 20.00 by sending an e-mail request to khz@essl.at. Only registered users can use the program without any restrictions: if not registered, fLOW will quit after 5 minutes.


An interpretation of fLOW by Ralph Lichtensteiger (2010)


  fLOW 4.0 (for Mac OS X - 10.6 or higher) new
released 11 May 2013: ZIP archive image (8.8 MB)

  fLOW 3.4 (for Mac OS X - 10.3.9 or higher)
released 19 Jan 2007: ZIP archive image (7.2 MB)

Legal Stuff

The fLOW sound scape is a composition of Karlheinz Essl. It is distributed as shareware and protected by copyright. As far as the entire content of the original distribution is not changed and no money is charged, this program may be spread freely and can also be included in CD-ROMs and Internet archives.

Softpedia Clean Award

More music software by Karlheinz Essl

  RP REplay PLAYer (© 2000-2013)
generative sound file shredder

REplay PLAYer is a computer program that de-constructs a given sound file and re-composes it by using realtime composition algorithms. It can be used as a tool to generate an infinite and every-changing sonic stream from a single sound file for artistic, 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.

And even more...


From: Music Electronics (Andy Murkin)
Date: January 2013
Also worth mentioning here, if you’re interested in this kind of thing, is the work of Karlheinz Essl. You can read about him on: Wikipedia and on his website. Of particular relevance in relation to the Black Widow project are two of the various programs Essl has created for sample manipulation. The first is called fLOW, and is described like this: ‘fLOW . . . generates an ever-changing and never repeating soundscape in real time that fills the space with flooding sounds that resemble – metaphorically – the timbres of water, fire, earth, and air. This ambient sound scape generator adjusts itself through various parameters and controllers that are represented in real time on your screen.’ Four samples are loaded and manipulated automatically via a comb filter, ring modulation, frequency shift and a flanger, and you can also load your own samples into it. You can read about fLOW and download it from http://www.essl.at/works/flow/download.html. I don’t remember how much it costs, but it isn’t very much, and well worth the money.

From: Matt Mower (aka rubymatt)
Date: Mar 5, 2006

Despite being very money conscious right now I shelled out $20 on Friday for Flow. I can't remember where I got the link from but I'm damned grateful because it's great. I now tend to leave it running while I work and I find it really helps me to get into flow state and ignore distractions. I also find it quite restful in the evening before bed. Definitely recommended.

From: Softonic
Date: Jan 14, 2004

Genera sonidos de agua, tierra, fuego y aire como fuente de inspiración
¿Necesitas relajación hundiéndote en los sonidos de la Madre Tierra, el aire, el agua, la tierra y el fuego unidos en un concierto de sonoridades ambientales, esto es lo que nos propone este generador de audio puramente naturista.
Naturista y configurable a nuestro gusto, gracias a su presentación bajo la forma de una tabla de mezclas, con cuatro canales para los cuatro elementos de la Madre Tierra, y una serie de filtros y efectos interfiriendo directamente sobre los algoritmos puestos en acción en esta increíble sinfonía.
Es realmente increíble lo amplio que puede llegar a ser el gran abanico de sonidos generados por fLOW, nunca repite y siempre sorprende, produciendo composiciones aleatorias y en tiempo real. Ofrece el soporte MIDI y permite importar ficheros MP3, brindando así una experiencia muy parecida a la que podríamos presenciar escuchando géneros musicales como la New Wave, o el Chill Out, puras sensaciones de relajación y expectación.

From: MACup
Date: April 2004

fLOW - Naturklang-Generator
Wer Meeresrauschen, das Blätterrascheln oder ein ähnliches Geräusch erzeugen möchte, sollte sich mit fLOW beschäftigen. Das Programm unterscheidet zwischen den Klängen aus den Bereichen Feuer, Wasser, Luft und Erde. Diese lassen sich frei variieren, mixen und mit Effekten versehen. Wer also noch eine Musikuntermalung für das letzte Urlaubsvideo sucht oder einfach entspannen und dabei chillige Ambience-Klänge genießen möchte, kommt um fLOW nicht herum. Gerade für die Hintergrundberieselung sollten alle Regler auf Auto stehen. (jk)

From: Liberation
Date: Feb 27, 2004

«Flow» artistique
Idéal pour les urbains en mal de nature, le générateur d'ambiances Flow crée en temps réel des paysages sonores toujours changeants, «emplissant l'espace avec des sons qui évoquent, métaphoriquement le timbre de l'eau, du feu, de la terre et de l'air». Ce petit logiciel pour Mac OS X mis au point par le compositeur, musicien et improvisateur autrichien Karlheinz Essl, permet de modifier certains paramètres mais le plus simple est de laisser le programme de musique concrète fonctionner tout seul. Il mixe tous ces drôles de bruits de façon aléatoire ; quelquefois, ça évoque un incendie, une tempête en mer, un clapotis de ruisseau, une corne de brume au milieu des fracas des vagues sur les roches ou les bourdonnements du trafic. (Marie LECHNER)

From: neural.it - hacktivism, e-music, new media art
Date: Jan 16, 2004

L'ambiente acustico fruito di fronte allo schermo è spesso riempito di ronzii, ticchettii o isolato nei files mp3 veicolati dalle cuffie o dalle casse, coprendo suoni e frequenze ottenuti da elementi naturali che risultano completamente dispersi nelle mura dell'ambiente urbano. Applicando l'essenza di simulazione della musica generativa fLOW è un software che visualizza costantemente il suo funzionamento, con i quattro elementi terra, aria, acqua e fuoco che vengono continuamente e automaticamente mixati. Disponibile per MacOS X il software riesce a produrre un sottofondo d'ambient in continua evoluzione, che può essere lasciato variare autonomamente o essere condizionato dai diversi parametri a disposizione. Un'intersezione di timbri organici e campioni imperscrutabili contribuisce a rendere lo stream di frequenze gradevole e l'effetto terapeutico che può esercitare sugli utenti, ampliando l'usuale range di frequenze e ritmi, giustifica una prova d'ascolto.

From: AmbiEntrance
Date: June 30, 2001

The ambient sound generator fLOW brings a literally neverending source of organic soundscapes to your Mac (G3 or better). In the words of its creator, the software "fills the space with flooding sounds that resemble - metaphorically - the timbres of water, fire, earth, and air." A nicely minimal flowchart offers some control... a "change material" button randomly loads each of four nodes with one the the "elemental" soundsources. Every so often I think I hear a passing bus or foghorn amongst the clatters and ripples, which adds to the musique concrete-ness of the continuous sonic outpourings. Download info is at the fLOW homepage. Thanks to Karlheinz for an intriguing freebie.

From: MACup
Date: Vol. 11/2001

fLOW 2.0 Software: Naturklänge aufnehmen und mixen
Wenn Sie "Ambience"-Klänge mögen, können Sie nun unter Anwendung von "fLOW" Ihre eigenen Geräuschteppiche und Natursoundkulissen produzieren. Das ungewöhnliche Programm des österreichischen Komponisten, Musikers und Improvisators Karlheinz Essl erlaubt die freie Komposition von Samples wie "Feuer", "Wind" oder "Meeresrauschen", die sich in der registrierten Version individuell laden und ansteuern lassen. Das Programm bietet zahlreiche Einstellungen zur Veränderung des Klangs und zur Gewichtung der Geräusche untereinander, sodass Sie beispielsweise mit einigen Aufnahmen aus Ihrem letzten Urlaub eine durchaus authentische Lautkulisse herstellen können. Leider sind in der unregistrierten Version die meisten Funktionen gesperrt, zum Anschauen und Ausprobieren regt das Programm jedoch allemal an. (aw)

From: Joshua Allen
Date: Monday, January 10, 2000 at 12:41:31 (PST)

(...) Oh, and the other great thing about these speakers is that I can finally use fLOW, the ambient sound generator. I guess it was originally some sort of artsy project, but now it's a Mac program that, in its own words, "generates an ever-changing and never-repeating soundscape in real time that fills the space with flooding sounds that resemble - metaphorically - the timbres of water, fire, earth, and air." It's got this complex control panel that you can mess with, but if you're smart you'll just leave it alone and let it mess with itself, so it mixes all these abstract sort of white noises together at random, so sometimes it sounds like a burning house or traffic going by or the ocean or whatever, but usually it sounds like an interesting mishmash of various things. I find it very soothing, especially when doing my transcendental meditation or deep groin bends or one-armed pushups or omphaloskepsis. (...)

From: PerversionTracker: apparently useless software
Date: January 6, 2004

fLOW 3.0.1
This ever so slightly Germanic ambient soundscape generator indubitably bears the distinctive mark of that modern master of software design, Dr. Karlheinz Essl. You can say many things about Dr. Karlheinz Essl, but it would be a hideous untruth to claim that he is unable to slap together some brown and blue boxes in a blighted imitation of standard GUI components for his own nefarious ends. Dr. Karlheinz Essl is capable of this, and much more.

While the lavatorial tones of fLOW’s burbling sets the scene, let us examine Dr. Karlheinz Essl’s use of sliders, which are apparently supposed to lunge wildly about of their own accord. In so doing, they periodically leave distasteful “ring around the slider” — a pixelly residue that would not be tolerated in a more refined application. Perhaps our rudimentary knowledge of Austrian culture is to blame.

Or perhaps Dr. Karlheinz Essl is too busy with his other pursuit, which can be most succinctly described with the following image:


Still, how can we dislike a man who pursues his gurgling attempts at “music” with such passion that he declares: I like an instrumental approach to electronics… the sensuality of grabbing things, using knobs and faders as if they had something to do with your body.

Well said, Dr. Karlheinz Essl, and for this, we award a space-filling 8.7, composed of equal parts water, fire, earth, and air, also taking into account the recipient’s individual socio-cultural context. Don’t ever stop grabbing things. Huzzah!

fLOW Home Works Sounds Bibliography Concerts

Updated: 19 Dec 2016