Ta-tata Case Study

Why Ta-tata Exists

The original goal was simple: keep time present without demanding attention.

Ta-tata began as a personal practice tool. As a beginner cellist, I found traditional audio metronomes distracting—especially when the metronome sound competed with the instrument’s pitch and tone.

Apple Watch’s haptic feedback suggested a different approach: feeling the beat instead of hearing it. With the Digital Crown enabling quick tempo changes, I built a watchOS metronome centered on wrist-based interaction, minimal UI, and reduced cognitive load during practice.

What v1 Shipped (2023)

The first release delivered a minimal implementation:

  • Haptic beat cues driven by a simple BPM → interval calculation

  • A simple interface for adjusting tempo

It was intentionally small—released in the spirit of experimentation as a learning artifact rather than a polished product.

Real Feedback and What It Revealed

Once released, user feedback clarified gaps I had underestimated.

User feedback surfaced a clearer problem than I anticipated:

  • Positive signals
    Some users appreciated the simplicity and the haptic-first concept.

  • Feature request
    A 4-star review asked for time signature support—an essential workflow need for structured practice.

  • Critical signal
    A 1-star review highlighted inaccurate timing and the absence of tap tempo, directly challenging the app’s core purpose as a metronome.

That review wasn’t noise. If a metronome can’t be trusted to keep time, nothing else matters.

Problems Identified

From feedback and extended use, several issues became clear:

  • Timing instability
    Small variances in interval scheduling caused the beat to feel unreliable over time.

  • Missing structured rhythm support
    Without time signature input, even basic practice scenarios were limited.

  • Setup friction
    Users couldn’t set tempo by feel during practice, which meant BPM changes disrupted practice flow.

  • WatchOS constraints
    Haptics suspend when the app goes to the background, and the small screen forces strict prioritization of controls.

Technical and Design Constraints

Accented pulses were originally planned for v2. On paper, they seemed necessary to support time signatures more clearly.

In practice, they failed. watchOS does not allow custom haptic patterns via Core Haptics. Instead, it provides a limited set of predefined WKHapticType feedback. These haptics introduce a noticeable delay—especially when layered or repeated with varying emphasis.

During real music practice, accented pulses disrupted the steady feel of the beat. The delay and overlap between haptics made timing feel uneven, particularly in compound meters like 6/8. Instead of clarifying rhythm, accents introduced ambiguity.

A second constraint compounded this issue: haptics require extended runtime support. Without explicitly managed runtime modes, haptic delivery can pause or become inconsistent when the app moves to the background or the watch display turns off.

Together, these constraints made one thing clear: complex haptic patterns were not musically honest on watchOS.

At that point, the problem was no longer about adding features—but about removing the wrong ones.

What Changed in v2

Version 2 focuses on correcting the core promise of the app by narrowing its scope and improving reliability.

  • A Simpler, More Honest Timing Model
    The timing engine was refined to reduce interval drift and improve stability. Each beat maps to a single, consistent haptic pulse. Accented pulses were intentionally removed after testing showed they interfered with steady beat perception due to system-level haptic delay and layering. One pulse equals one beat.

  • Time Signature Support
    Time signature input was added to support structured practice workflows. The time signature provides context—but does not introduce accented haptics or rhythmic patterns that the system cannot deliver reliably.

  • Tap Tempo
    Tap tempo was added to allow quick BPM input by feel. It lives in a modal context to avoid cluttering the main interface and to preserve focus during practice.

  • Runtime Reliability
    Extended runtime handling was prioritized to keep haptic feedback active and consistent, even when the watch display state changes—addressing a key source of inconsistency in v1.

  • UI Prioritization on a Small Screen
    The Apple Watch’s limited display required strict hierarchy decisions:

    • Play/pause remains the dominant control

    • BPM and time signature are directly accessible

    • Tap tempo is available, but secondary

    • Non-essential elements were removed

    Every visible control had to justify its presence.

Trade-offs and What’s Still Unsolved

Ta-tata intentionally avoids:

  • Complex rhythmic patterns

  • Advanced customization or practice modes

  • Feature-heavy customization

  • Analytics or cloud features

  • Extended backend services

These are not omissions—they’re boundaries. The app is positioned as a pulse reference, not a rhythm instructor or full practice suite.

Takeaways and What It Means

  • Iteration matters
    Honest feedback pushed the app away from a neat idea toward real utility.

  • Accuracy first
    A metronome must keep time — everything else is secondary.

  • Constraints define the product

    watchOS haptics shape what is musically honest. Designing around those constraints mattered more than feature parity.

  • Small screens demand design discipline
    Prioritize core controls; defer extras to modal contexts or future case studies.

Ta-tata v2 doesn’t try to do more. It tries to do one thing correctly.
That shift—from an interesting idea to a reliable, narrowly scoped tool—is the real outcome of this iteration.