Hook up your instruments, if applicable. To connect an instrument cable directly to your computer, attach a one-quarter to one-eighth inch adapter to the end of the cable and plug it into your Line-In port while plugging the opposing end into your instrument. Otherwise, you can plug your instrument(s) into a USB interface and plug the interface into any available USB port.
Open Cubase by double-clicking the LE4 icon on your computer. Create a new song project by clicking "File" on the menu bar and selecting "New Project" from the list.
Configure Cubase to receive input from your connected instrument. Click "Devices" on the menu bar and select "Device Setup" from the drop-down menu. Select the "Device Port" option and choose your instrument, interface or other input device from the list. Click "OK" when you finish making your selection.
Select a track for recording. Your tracks will appear on your main window as rectangular recording spaces, each with a number and a series of editing options. To select a track, click it once.
Select your input source for your track. Click the "Edit Channel Settings" button on your selected track, click the "Input" button that appears on the "Channel Mixer" and select your input source. If using a MIDI instrument, you can select a software synthesizer from the list and create a custom sound setting.
Click the red "Record" button on your selected track to begin the recording sequence. When you finish recording, click the "Stop" button. To create multiple layers of music, repeat the recording process on subsequent tracks.