Studying massive star populations with SYMPHONY

The SYMPHONY project is dedicated to investigating the internal structure and dynamical processes of massive stars, with a central focus on asteroseismology as a key insight tool. Understanding these stellar interiors is crucial to addressing some of the most persistent and complex questions in stellar astrophysics, including the evolutionary pathways of blue supergiants and the physical origins of stochastic low-frequency variability observed in many massive stars. In this presentation, I will share preliminary results from an ongoing observational program using the HERMES spectrograph, targeting a diverse population of massive stars. By combining high-resolution spectroscopic data with complementary photometric observations from TESS, I assess various stellar properties and phenomena—such as pulsation behaviour, binarity, emission-line features in Oe/Be stars, chemical peculiarities, and magnetic fields from rotational modulation. This multi-faceted approach not only enhances our understanding of individual stellar characteristics but also contributes to the identification of promising targets for future in-depth studies. These include candidates for detailed asteroseismic modelling, investigations into circumstellar disk activity in Oe/Be stars, and explorations of the interplay between magnetism and pulsations in massive stars. Through this work, SYMPHONY aims to lay the groundwork for next-generation studies of massive stellar evolution and variability.