New Selection help when duplicating audio

Hi, I’m wanting to apply a filter out to a selection of audio, so I’m attempting to do this by selecting the area of audio I want, and then duplicating it, applying a filter and fade-in to the duplicated audio, and a fade-out of the original audio. My problem is with selection. When I first duplicate, I have the exact audio I want selected in both tracks. However, when I attempt to select a single track to only apply the effect to the track I want, I’m losing my selection of the audio within the track. Very frustrating. I find I often want an undo/redo for the selection process but it doesn’t exist. So please, how do I simply duplicate a selection of audio (within a recorded dj set), and duplicate it so I can apply a gradual filter to a transition. I’m sure there’s a procedure that will make this a lot easier than just writing down the start/end times.

Thanks in advance. /David

If you are selecting the track by clicking above Mute / Solo, that selects all the audio in the track. To select a track retaining the selection region, hold SHIFT then click above Mute / Solo.

Alternatively, hit ENTER on your keyboard to deselect the track, UP or DOWN arrow on your keyboard as appropriate to move the yellow focus border to the other track, followed by ENTER to select that track.

You can save and restore a single region. See Audacity Manual.

Gale