YouTube prioritises videos in their search that have a high watch time as it shows the video is of quality content and engages viewers.
We recommend monitoring your Audience Retention reports under YouTube Analytics so you can see which of your videos are the best performing and which have areas for improvement.
You can view these reports per video, ideally, you want to have your "Average Percentage Viewed" as close to 100% as possible. This is never going to be achievable, however, this is the ideal scenario.
To put this report into actionable steps to increase your watch time, you can identify the types of videos that are performing well, theorise what it is about these videos that the audience is responding to and concentrate on this type of content when creating new videos.
You can also identify areas of weakness in certain videos, if you see a video with a high drop off rate at a certain point, try to review the video and see what is causing viewers to move on. You can then avoid this type of content when creating new videos.
Specific to music videos, keep the videos short and engaging, avoid long intros and upload radio edits.