Understanding how brain networks operate across different frequencies during cognitive tasks, and how these dynamics change with age, remains a central challenge in cognitive neuroscience. While previous studies have focused on resting-state activity and passive listening, less is known about frequency-specific brain dynamics during event-related tasks that require active memory engagement. In this study, we extend the recently developed FREQ-NESS analytical pipeline by adapting it to event-related task and resting-state source-reconstructed magnetoencephalography (MEG) data from 140 healthy participants. This method quantified the variance explained by frequency-specific brain networks, their spatial organization, and associated time-resolved power estimates. We found significant effects of age, condition, and their interaction in the variance explained by leading components at 8.6, 10.0, and 20.0 Hz. Older adults exhibited peaks at 8.6 and 10.0 Hz across both rest and task, while younger adults displayed a task-related reduction, suggesting a different organization of brain networks during memory processing with age. Time-frequency analysis revealed age- and condition-dependent desynchronization in the alpha and beta bands (7.1-22.9 Hz). These findings demonstrate the effectiveness of the adapted FREQ-NESS pipeline for event-related tasks and highlight the importance of frequency-resolved network analysis for characterizing age-related changes in active auditory memory processing.