Comparison

MuSA_RT vs FD

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

MuSA_RT

This app visualizes music tonality in 3D using advanced algorithms. It analyzes audio from your microphone to identify chords and keys, displaying them with a rotating camera or in augmented reality.

Highlights
  • 3D tonality visualization
  • Audio analysis for pitch and context
  • Chord and key identification
  • Augmented Reality mode
  • Smooth camera rotation for unobstructed views
Read full description

MuSA_RT applies music analysis algorithms rooted in Elaine Chew’s Spiral Array model of tonality, which also provides the 3D geometry for the visualization space. The app analyzes the audio signal received from a microphone to determine pitch names, maintain short term and longterm tonal context trackers, each a Center of Effect (CE), and compute the closest triads (3-note chords) and keys as the music unfolds in performance. The 3D view presents a graphical representations of these tonal entities in context, smoothly rotating the virtual camera to provide an unobstructed view of the current information. These graphics can also be visualized in an experimental Augmented Reality mode on compatible devices.

About

FD

This app is a semi-modular audio effect plugin featuring dedicated filter, delay, and modulation sections. It allows for the creation of rhythmic filter sequences and a wide range of complex audio effects through its flexible modulation matrix.

Highlights
  • Semi-modular effect plugin
  • Modulated filter section
  • Delay stage
  • Step sequencer
  • Low Frequency Oscillator
  • Mod matrix
  • Tempo sync
Features
Read full description

FD-1 is a Semi-Modular Effect Plugin including dedicated Filter, Delay and Modulation sections. At it's core, FD-1 is designed to create filter rythms and grooves by first sending the signal through a modulated filter section before feeding it to a delay stage but it goes much further than that. Built-in Step Sequencer and Low Frequency Oscillator serve as modulation sources and are ideal for creating rythmic filter sequences either free running or tempo-synced to a host application. However, due it's semi modular nature, not just filter cutoff but every control within FD-1 can be a modulation target allowing for an increased range effects and combinations ranging from Chorus and Flanger type effects over Analog and Tape Style echos to complex Stutter and Repeat effects. Overview: - VA Multi Mode Filter with 2 & 4 Pole options - Digital Stereo Delay with Tempo Sync and Time Range Control - Analog Style Step Sequencer - Low Frequency Oscillator - Easy to use Mod Matrix - Input Low-Cut and Drive Controls - Individual Return Levels for Filter and Delay Connectivity: - Standalone - AUv3 - IAA - AudioBus (Filter) MIDI: - Tempo Sync - CC Control Requirements: - iOS9+ - iPad 4th generation or newer

Screenshots

MuSA_RT2 screens
FD4 screens

Verdict

The call

The clearest difference is review sentiment: FD at 67% against MuSA_RT's 0%. FD also leads on ratings volume (32 vs 1) and iOS requirement (9.0 vs 15.6). MuSA_RT's advantage is price (Free vs $9.99) and rating (5.0 vs 4.6). On update cadence, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

MuSA_RT is free to download; FD costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

MuSA_RT holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: FD has 32 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 0% of MuSA_RT's written reviews are positive against 67% of FD's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

MuSA_RT ships an update every 3 months, FD every 4 months. The most recent releases landed on June 5, 2026 and September 12, 2026 respectively.

Scorecard6 real differences · 4 level
MuSA_RT versus FD: the parameters behind the verdict, then further details
ParameterMuSA_RTFD
PriceFree — better$9.99
Rating5.0 (1 ratings) — better4.6 (32 ratings)
Positive reviews0.0% of reviews66.7% of reviews — better
Number of ratings132 — better
Update frequencyEvery 3 months — betterEvery 4 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPad, iPod
Requires iOS15.69.0 — better
Further details — not scored
Size3 MB61 MB
Age rating4+4+
DeveloperAlexandre FrancoisKai Aras

Customer experience

MuSA_RT

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive0.0%
Neutral50.0%
Negative50.0%

FD

All ratings32 ratings
Positive90.6%
Neutral0.0%
Negative9.4%
Written reviews9 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

In-app purchases

None

MuSA_RT

No in-app purchases

None

FD

No in-app purchases

Questions

Is MuSA_RT free?
MuSA_RT is free to download, with no in-app purchases.
Is FD free?
FD costs $9.99, with no in-app purchases.
Which has better reviews, MuSA_RT or FD?
MuSA_RT is rated higher. MuSA_RT averages 5.0 out of 5 from 1 ratings, while FD averages 4.6 from 32 ratings.
Do MuSA_RT or FD have ads?
Neither MuSA_RT nor FD shows ads.
Which is updated more often, MuSA_RT or FD?
MuSA_RT ships an update every 3 months, and FD every 4 months. Most recently, MuSA_RT was updated on June 5, 2026 and FD on September 12, 2026.

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