The Pórtico de la Gloria is one of the masterpieces of Romanesque, placed inside the Cathedral of Santiago de Compostela. The monument consists of three arches. On the left arch there is represented the Old Testament scriptures. Hell is depicted on the right arch, and the central tympanum represents Glory. Surrounding the central arch there are 24 elders tuning musical instruments, an image that is described in the Book of Revelation. These figures are essential to understand how medieval instruments were, and the music people played with them, because they are one of the most accurate representations of musical instruments from these centuries. This figures stand between 6 and 9.5 meters from the ground, making it impossible for visitors to distinguish (looking from the ground) small details that characterize each elder, and recognize the instrument that each elder is tuning. Among these details it is important to notice the remains of polychrome as the Portico de la Gloria was originally coloured. Over several centuries it has suffered the ravages of time and humidity, being restored several times using different colour schemes whose small remains are still preserved over the stone.

Below the monument there is a crypt that houses a museum based on the “Pórtico de la Gloria”, being the musical instruments an important part of its contents.

Several museum features, such as sculptures, ceramics, or in our case, stringed instruments have specific criteria concerning their protection, maintenance and preservation to ensure their proper care and restoration. Due to these criteria, visitors must observe the element in a glass show case that prohibits any kind of interaction limiting the didactic purpose of the exposition.

This paper presents an interactive application developed for the public presentation of the instruments of the Pórtico de la Gloria in a museum. The application allows visitors not only to explore the virtual reconstructed stone figures of the elders but also the interaction with the virtual reconstructed instrument, listening to its sound and moving it freely in space.

The main project goals were creating a faithful virtual reconstruction of the elder’s instruments and developing a tangible interface to interact with the system, focusing on its usability for inexpert users.

For this purpose a scanned 3D model of the elders has been textured focusing on the importance of the polychrome remains that are still preserved on the monument. A virtual reconstruction of the 18 different instruments has also been performed based on the drawings, sketches and photographs of the reconstruction made by López Caro.

It has also been developed an intuitive tangible interface, based on computer vision and AR markers, to allow any inexpert user to interact with the system.

The result is a system enriches the experience of visiting the Portico de la Gloria giving to the visitor information about the characteristics, history and sound of each instrument represented in the monument in an interactive and more attractive manner.