For creating your music, besides the recording software, you’ll need lots of sounds, which are also known as sound libraries. Most of these sounds are available as VST plugins which can be triggered using a midi controller.
VST stands for Virtual Studio Technology, which is an interface for integrating software audio synthesizer and effect plug-ins with audio editors and hard-disk recording systems.
To be able to compose for any genre, you need lots of sounds so that you can do full justice to your creative ideas.
You get access to various tools which are useful to the immediate to advance producer. You could be a hip-hop producer, a DJ, a remix artist, a vocalist, or even a film/audio engineer. You can make any kind of beats with the various VST plugins that are available.
These new range of tools will help you out to create music for various needs.
But then it is not just about sounds, there are VSTs that are available to add various kinds of effects as well, such as equalizer, harmonizer, etc.
VST plugins are generally run within a Digital Audio Workstation (recording software), providing the host application with additional functionality.
As you can see, most VST plugins can be classified as either instruments (VSTi) or effects.
Plugins from Universal Audio (UAD) are among the best, that are available for recording purposes, and mimic the sound of vintage/classical gear.