Add your own music to an AI video remake
Choose a short visual section for your song, edit the soundtrack separately, and check timing, mouth movement and the final audio mix.
An AI performance clip and a finished song are two different ingredients. CastRemix can provide a visual draft based on photos and a motion reference. Put that draft beside your chosen audio in an editor when you need the final video to use a specific recording.
Pick the musical moment first
Choose a short part with a clear beginning and end: a hook, a pause before the chorus or one instrumental phrase. Decide whether the shot should feel energetic, quiet or comic. A matching visual mood is often more useful than a random performance cut to the right duration.
Use audio you have permission to include in the final publication. Owning the photo does not establish rights to an unrelated song. If you plan to add a track from a posting app's library, check the terms that apply to that use rather than assuming every version of the track has the same permissions.
Choose visuals that do not depend on new lyrics
A dance clip can accompany a song without implying that the performer sings its exact words. The Hotel Lobby duet uses a performance reference, but its visual workflow does not write lyrics or guarantee lip sync to your recording.
If the concept requires a face articulating every word, assess that requirement separately before generating. A loose rhythmic match is different from speech synchronization. Adding a new audio file afterward does not change the mouth movement already present in the video.
Generate the scene, then edit the soundtrack
Prepare the photos and follow the selected template's requirements. Keep the final musical segment available in your editor rather than trying to turn a fixed template into an audio-upload workflow. Download a result that passes your visual review.
On the editing timeline, place the video and chosen audio on separate tracks. Listen for any audio already in the downloaded clip; mute or lower that track if it conflicts with the new recording. Do not judge the file's sound solely from a browser preview that may have been muted.
Align a few visible beats
Find a useful action such as a hand raise, a step landing or a glance. Align that moment with one musical accent, then play the whole section to check whether the remaining movement still feels natural. Small trims are easier to evaluate than repeated speed changes across the entire clip.
If the action cannot fit the music without obvious distortion, choose another section or another visual. Forcing every motion onto every beat can make hands, facial movement and body rhythm look unnatural. A clean cut between two shots can be more convincing.
Check the exported mix on another playback surface
After export, listen through headphones and the device speaker if both matter to your audience. Check that the start is not cut off, the ending is intentional and the source audio does not play unexpectedly beneath your track.
Add captions separately when needed, and label the fictional or AI-created nature appropriately for the context. For multiple scenes, use the longer-video sequence plan. The final recording, editing choices and distribution remain part of your own publishing workflow.