A photolithography tool including an optical system for transmitting a beam of radiation toward a substrate is presented. The materials may be used as T1-weighted andor T2-weighted MRI contrast agents for imaging, including cellular imaging, in clinical diagnosis and biomedical research applications. The field effect transistor includes gate, source and drain electrodes, and a source-side parasitic capacitance formed between the gate and source electrodes and a drain-side parasitic capacitance formed between the gate and drain electrodes of the field effect transistor have different capacitance values. A recording time of the input audio based on a time point at which the user input has been received and the time position on the musical score designated by the user input are stored into a storage device in association with each other.