Question: I need a tool to shorten or lengthen music tracks without losing the melody and vocals, can you suggest something?

If you want a tool to trim or extend tracks without mangling the melody and vocals, TuneBlades is a good choice. It's an intelligent audio editing tool that can automatically shorten or extend tracks, preserving the original melody and vocals. It can handle high-quality audio formats like mp3, wav and m4a, and is geared for content creators who want to be able to rapidly and easily manipulate tracks. TuneBlades offers a range of pricing options, from a one-time purchase to subscription plans.

Another tool that could be useful is Cryo Mix, an AI music mixing and mastering service. It's more focused on improving sound quality, but its AI Mixing tool lets you control parameters like vocal volume and pitch correction, which could be useful for preserving the quality of your tracks. It also has an AI Audio Separator tool that can pull out individual stems from a single audio file. That could be useful if you want to isolate specific elements of a song.

If you want to flesh out your music with AI-generated tracks, check out ExtendMusic. The service uses generative AI to create music that's related to what you originally uploaded. It's free to start, so musicians can try out AI-generated music without having to pay up front. That could be useful for finding new ideas and sounds to spice up your tracks.