# User Guide: Virtual Harpsichord by Conrad Fleischer (1720)

## 1. Project Background

In 2021, the Museu de la Música de Barcelona launched a project to improve public access to historical instruments. The goal was not just to exhibit or document them, but also to allow users to explore their sound and musical potential using virtual interfaces such as those at www.teclats.cat.

Since 2023, one such interface has been installed at the museum as the electròfon híbrid. Initially built on GrandOrgue, it soon became clear that a custom open-source platform based on WebMIDI would better suit the museum’s needs. Details available at resum.htm.

## 2. Virtual Restoration of the Fleischer

The Carl Conrad Fleischer harpsichord (1720) at the museum is restored but cannot be played due to its fragile state. Each string was tuned and recorded individually. A corrective model—based on a similar Zell harpsichord—was applied to simulate sympathetic resonance and body tension.

The result is a virtual reconstruction that sounds better than would be physically possible. See the process.

## 3. Expressiveness and Register Timing

Good harpsichords exhibit dynamic nuance. When multiple stops are engaged, pressing a key softly causes slight timing differences between registers, creating a gentler sound. This interface replicates that behavior.

Using a MIDI keyboard or clicking on-screen keys (top = soft, bottom = loud), you can feel this effect. A dropdown allows adjusting this timing gap from 127 ms to 0.

The default order is usually 4', 8' I, 8' II. However, Joan Martí i Llobet experimented with 8' I, 4', 8' II and even 8' I, 8' II, 4', based on sonic balance. All three options can be selected in this interface.

## 4. Temperaments and Detuning

The platform includes various historical temperaments, plus a manual mode that simulates an out-of-tune instrument. Clicking the smiling skull icon lets you choose the desired detuning level.

## 5. Manual Tuning

In manual mode, each string can be tuned individually using the virtual tuning wrench (slider). Select a note from the upper clavichord layout and adjust within ±1 semitone. Overstretching breaks the string, which is then replaced after one minute by an AI-powered virtual luthier.

You can use your computer keyboard to play notes while tuning.

## 6. Saving and Restoring Tunings

Use the backup manual setting and restore manual setting buttons to save and load custom tuning configurations for later sessions.

## 7. Acoustic Spaces and Spatialization

The harpsichord can be played in different virtual acoustic spaces using convolution reverb. Choose a venue from the dropdown to hear how it affects the sound.

A distance slider adjusts the balance between dry and reverberant sound. The background image updates automatically to show a visual of the selected acoustic space.

This interface and others are available online at: www.casacota.net/mostres/

## Credits

This interface was developed by Pere Casulleras as part of the Museu de la Música de Barcelona’s instrument virtualization project, with collaboration from Joan Martí i Llobet.

Attribution-NonCommercial-NoDerivs 4.0 International