# SOLO  Nr.19

> Digital implementation of Stockhausen's algorithmic music composition for soloists. (iPhone/iPad app by apeSoft.)

- Source: https://appshunter.io/ios/app/solo-nr19/id884781236 (this page in markdown: same URL + `.md`)
- Developer: [apeSoft](https://appshunter.io/developer/464660782)
- Category: Music
- Price: Free with in-app purchases
- Rating: 4.40/5 from 7 App Store ratings · 5 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 59 MB
- Languages: American English
- Released: 2014-07-23
- Data updated: 2026-08-26
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/solo-nr19/id884781236/reviews.md

## What is SOLO [Nr.19]?

*** This app is for the Musician who want to play SOLO [Nr.19] of Karlheinz Stockhausen for Study, Live Performance, Concerts, Lessons etc... It have not sense to employ this app otherwise. 
You can hear fully the first version performed by Enrico Francioni (Contrabass) and the second version performed by Simonetta Sargenti (Violin)
***

SOLO [Nr.19] is an algorithm that aims to implement digitally the original analog set-up for the performance of six versions of Solo für melodieninstrument mit rückkopplung by Karlheinz Stockhausen.
The original composition was conceived for five persons. Four technicians plus the main instrument performer. SOLO [Nr.19], performs the work of four technicians for each of the six Stockhausen's versions.

"Solo" (für Melodieninstrument mit Rückkopplung) by Karlheinz Stockhausen is a piece written for any solo melodic instrument and employs a feedback system to allow the soloist to create polyphonic music. Written in 1966 with its world premiere in Tokyo in the same year, its origin dates back to the same period as the composer's work "Kontakte". "Solo" uses the technique of recording onto tape with a single head together with a moveable arrangment of playback heads, allowing for the creation of complex sounds through accumulation.
The original version (with an analog technical set-up) requires a solo instrumentalist as 4 assistants (technicians): three assistants operating the opening and closing of sliders (L/R channels)–respectively the microphone, delay-line and output–and an assistant for the change of time values of the taps in the delay-line. During a performance a part of what the instrumentalist plays is captured by a two-channel recorder. Through a feedback circuit, the sections are recorded more or less densely stacked and processed with a variable delay time; the result is then played by two sets of speakers and mixed with the direct sound of the soloist.
The score (Universal Edition-Wien, 1969) consists of six pages of music and six pages of Form- Schema (the number six can be considered a key element), in addition to explanatory notes (very detailed) for the performance the composition. "Solo" is one of those compositions by the author employing "controlled alea" as a compositional language. Indeed many choices are left to the soloist and cover almost all the events: from the selection of a version, the positioning of the material, the types of tonal variation requests, the order of pages and more. In reality these faculty are provided as input by the composer through the management of macroscopic or microscopic order parameters, restricting the possible versions (virtually infinite) at a predefined or definable set of possibilities. In this piece, the role of the interpreter is very important in the creation of a performance that is always unique and unrepeatable every time.

## Key features

- Digital implementation of analog setup
- Algorithmic composition performance
- Feedback system for polyphonic music
- Study and live performance tool
- Two performance versions included

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| SOLO  Nr.19  Live Performance | Free | one-time |


## Recent user reviews (5 of 5)

All indexed reviews: https://appshunter.io/ios/app/solo-nr19/id884781236/reviews.md

### 5/5 — Awesome !

*2020-04-23*

I’m really happy with this app, I’m a fan of Stockhausen, so thanks a lot for your work.

### 1/5 — 1 star now; 5 stars a couple years ago

*2019-09-06*

Used to be a neat app, but at some point the default sample rate on my iPad and iPhone was switched from 44.1 to 48 (I have to assume as part of an update, was nothing I did manually), and since then Solo has not worked, despite following directions to change the sample rate back to 44.1.  Paid for the full version way-back-when, but is now seemingly DOA.  Shame, was really cool, and all other sound apps by this developer are amazing.

### 5/5 — iVCS3

*2018-04-13*

Ich bewerte hier zwangsweise den iVCS3, da ich ihn von den Entwicklern als Promo geschenkt bekommen habe. Apple hat es leider unterbunden, dazu eine Bewertung abgeben zu dürfen.

Daher an die Entwickler: 
Vielen ❤️ Dank!
Das Teil ist schlichtweg der Burner. 

(An den User, mit der doppelten 0 im Namen. Häng noch eine weitere dazu, du hast nämlich tatsächlich Null Ahnung.)

Zu SOLO [No.19] kann ich noch keine Meldung abgeben. Sieht aber spannend aus, was KH. Stockhausen da fabriziert hat.

### 1/5 — IAP for Audiobus?

*2014-07-25*

Doesn't that violate the Audiobus license?

"No In-App Purchase For Audiobus Support In Apps"

**Developer response:** The IAP for Audiobus has been removed­. You can up­gra­de to the FULL ver­sion to play all six CY­CLES..

### 4/5 — Classy stuff from apeSoft

*2014-07-24*

Another leftfield offering from a great developer. Simple, yet surprisingly deep exploration of a Stockhausen work.

## Frequently asked questions about SOLO [Nr.19]

### What is SOLO [Nr.19] used for?

SOLO [Nr.19] is designed for musicians to study and perform Karlheinz Stockhausen's 'Solo für melodieninstrument mit rückkopplung'. It digitally recreates the complex analog setup required for this algorithmic composition, enabling soloists to create polyphonic music.

### What musical piece does SOLO [Nr.19] relate to?

SOLO [Nr.19] is an implementation of Karlheinz Stockhausen's 'Solo für melodieninstrument mit rückkopplung', written in 1966. It uses a feedback system to allow a solo instrumentalist to generate polyphonic music.

### What versions of the music are available in SOLO [Nr.19]?

SOLO [Nr.19] provides two distinct versions of the composition for study: the first version performed by Enrico Francioni on Contrabass, and the second version performed by Simonetta Sargenti on Violin.

### Does SOLO [Nr.19] require any special equipment to use?

SOLO [Nr.19] digitally implements the original analog setup, so it aims to replace the need for extensive external technical equipment. It allows the soloist to manage the complex feedback and delay systems through the app itself.

### Is SOLO [Nr.19] suitable for beginners in music?

The app description explicitly states that it 'have not sense to employ this app otherwise' than for musicians wanting to study or perform this specific Stockhausen piece. It is intended for those with a specific interest in this complex algorithmic composition.

### What devices does SOLO [Nr.19] support?

SOLO [Nr.19] is supported on Mac, iPhone, iPad, and iPod devices, indicating broad compatibility within the Apple ecosystem.

### How often is SOLO [Nr.19] updated?

The latest version of SOLO [Nr.19] is 2.2.2, which was last updated on October 3, 2021. This suggests a moderate update frequency.

### What is the user rating for SOLO [Nr.19]?

SOLO [Nr.19] has a user rating of 4.4 stars, based on 7 ratings. This indicates generally positive user sentiment among its current users.

## Version history (last 5 releases)

### 2.2.2 — 2021-10-03

+ Ready for iOS 15
+ iPhone UI fixed

### 2.2.1 — 2021-09-29

+ Ready for iOS 15

### 2.2 — 2020-09-27

- iOS 14 ready
- Reactive audio when disconnecting from IAA, workaround for iOS 13
- Audiobus/IAA, improved MIDI Receive
- Updated Audiobus SDK
- Updated AudioCopy SDK
- Updated ABLink SDK

### 2.1.1 — 2020-03-30

Added Inter-App Audio

### 2.1 — 2020-03-23

Demo can play now with any Sampling Rate
Audio stability Improvements
Some minor tweaks

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## More apps by apeSoft

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All apps by apeSoft: https://appshunter.io/developer/464660782

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-26.*