Galactic globular clusters (GGCs) are now known to have some degree of chemical complexity indicating that they do not consist of a "single" stellar population. Instead, some stars have an atmospheric composition showing evidence of material processed by nuclear reactions. Up to now, most of the spectroscopic investigations on the topic of multiple populations chemistry were based on high-resolution spectroscopy obtained with, for example, FLAMES and UVES. We obtained millions of stellar spectra in 26 GGCs with the GTO survey on Globular Clusters. Even though the spectral resolution of MUSE is significantly lower than what is typically used in literature work, the sheer amount of data collected allowed us to gain significant insights on the topic of stellar chemistry in GGCs. We combined information from the MUSE spectra for hundreds of stars per clusters with the high-precision multi-color photometric catalogs from the Hubble Space Telescope to study, in unprecedented details, the metallicity properties of the multiple populations in GGCs. Among our thousands of stellar spectra in all GCs, we also identified hundreds of candidate Li-rich stars, while up to now only a handful of Li-rich stars in GGCs are known in the literature. In this talk, I will present an overview of our past and current work on the topic.