Choose a song that you want to create dance steps for and check its format. Compatible formats include .mp3, .ogg or .wav. After choosing your song, find the Songs directory for Sound Forge, which is located in the program's main folder. Copy your selected song file to the Songs folder, then open Sound Forge. Once the program is open, click on File, then Open File, after which you will be able to find your song in the Songs directory.
Open your song and a display will appear that shows the sound map. To identify where the song's beats are, look for the vertical spikes in the sound map. Isolate a section of the song (four bars work well) for your dance moves: click on the first beat and then hold "Shift" and click the last beat. This will highlight the entire section of the music. To get an accurate reading of the beats, zoom in until you can see the exact point where each beat begins and ends. Keep in mind that, for the majority of pop songs, each bar has four beats, so isolate sixteen individual beats for a four-bar section.
Calculate the beats per minute (BPM) for your selected section of the song. Observe in the bottom right corner of the program that it has a reading of the total duration of your selection. Count the number of beats in your selection and divide it by the number displayed in the bottom right, then multiply the result by 60 for the beats per minute rate of your selection (StepMania will need this figure for accurate playback). Next, calculate the space between the beginning of the song and the beginning of the actual beat (StepMania also needs this figure for proper playback). Place the cursor on the first beat of the song and observe the time reading -- this is called the offset time and can range from under a second to several seconds.
Create a text file (Notepad works well for this) and include the following information: Title, Artist, BPMS and Offset. Each category should have its own line and each piece of information should be preceded by a # sign and followed by a colon and the corresponding information. The offset category should always be a negative number. When you have completed all of the information for the text file, save it as an .sm file in the same folder as the music file that have been editing. Your StepMania file is now ready for playing in StepMania.
Close Sound Forge and open StepMania. Open your new file and then go to the program's editing option. Under this option, you will be able to assign dance steps to each beat -- you will see a display that lists the total beats and what dance step is assigned to each. You will be given a key that lists all the possible steps that can be selected for each beat. Work your way through the song, assigning steps. Once you are finished editing, play the song and follow the dance steps. If you want, you can always go back to the editing option to change any of the dance steps.