index.html

<link rel="stylesheet" href="app.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:400,800">
<div id="container">
    <div id="hook"></div>
    <h1>Play Music</h1>
    <input type="file" id="files" name="files[]" multiple/>
</div>
<script crossorigin src="https://unpkg.com/react@15/dist/react.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@15/dist/react-dom.js"></script>
<script src="https://npmcdn.com/babel-core@5.8.38/browser.min.js"></script>
<script src="https://soulwire.github.io/sketch.js/js/sketch.min.js"></script>
<script src="app.js"></script>
<script type="text/babel">
    const PlayButton = (props) => {
        const className = props.isMusicPlaying
            ? 'play active'
            : 'play';
        return (
            <a
                href="#" title="Play video"
                className={className}
                onClick={props.onClick}
            />
        );
    };

    class Container extends React.Component {
        constructor(props) {
            super(props);
            this.state = {
                isMusicPlaying: false,
            };
        }

        // Отреагировать на щелчок мышью.
        handleClick() {
            this.audio[this.state.isMusicPlaying ? 'pause' : 'play']();
            this.setState(prevState => {
                return {
                    isMusicPlaying: !prevState.isMusicPlaying,
                };
            });
        };

        render() {
            return (
                <div>
                    <PlayButton
                        onClick={this.handleClick.bind(this)}
                        isMusicPlaying={this.state.isMusicPlaying}
                    />
                    <audio id="audio" ref={(audioTag) => {
                        this.audio = audioTag;
                    }}/>
                </div>
            );
        }
    }

    const placeWeWantToPutComponent = document.getElementById('hook');
    ReactDOM.render(<Container />, placeWeWantToPutComponent);
</script>