The opening day of the San Isidro festivities in Madrid was marked by intense musical activity, with concerts offering a wide range of genres for all audiences. The Madrid City Council's Department of Culture, Tourism, and Sport designed a program that blended tradition with the latest sonic trends.

At the Pradera de San Isidro, the traditional heart of the celebration, the night kicked off with a performance by Vicente Calderón, who connected with the audience through his energy and humor. He was followed by Rubén Pozo and Los Chicos de la Curva, presenting their album 50town and revisiting their popular hits. The evening concluded with a set by DJ Fernanda Arrau, transforming the space into an open-air dance floor with electronic rhythms.

The Las Vistillas gardens were dedicated to new musical trends. The El Nuevo Madriz showcase featured sets by DJ Ruptura and Pablito Tedeka. Later, Rebe presented her experimental pop universe, and the night closed with Hens, a prominent voice of the new Spanish pop-rock wave, delivering an energetic and relatable performance.

Plaza Mayor hosted the celebration of LOS40's 60th anniversary with a concert bringing together artists from different generations of Spanish music. For four hours, the audience enjoyed a journey through national hits with performances by Miguel Ríos, Alejo Stivel, Sole Giménez, The Refrescos, Celtas Cortos, OBK, Amistades Peligrosas, Marilia, Nena Daconte, and DePol.

Matadero Madrid came alive with the first major street party, evoking traditional Madrid with the lively atmosphere of an organ grinder and the Federación de Grupos Tradicionales Madrileños. The Orquesta Nuevo Versalles energized the night with a festive and participatory repertoire, reinforcing the inclusive spirit of the celebration.

Additionally, the Teatro de Autómatas opened, an attraction combining craftsmanship and technology to recreate costumbrista and cabaret scenes through moving mechanical figures, adding a playful and traditional dimension to the festive program.