measured in amperes, and in wires it is carried by electrons. Charge flows when there is a voltage, a difference in electric potential measured in volts, between two points; a battery maintains such a difference between its terminals. Materials resist the flow to different degrees, and that resistance is measured in ohms. A circuit is a closed loop through which current can flow from the source, through components, and back again; break the loop anywhere and the current stops. Safety first: low-voltage battery circuits are fine for learning, but mains electricity can kill, so never experiment with it." } ] }, { "id": "arts", "name": "Arts & Music", "host": "music", "blurb": "Making and understanding art: music theory and production, songwriting, visual art and the stories behind them. Next door to the Music Studio Tower and Solid Sound.", "courses": [ { "id": "mus101", "title": "Music Theory I", "host": "music", "desc": "Notes, rhythm, scales, keys, intervals and chords: the grammar behind the songs you love.", "lessons": ["Pitch, notes and the staff", "Rhythm, meter and tempo", "Major and minor scales", "Intervals", "Triads and chord progressions"], "intro": "Music is organised sound, and pitch is how high or low a sound is, set by how fast it vibrates; the A above middle C is usually tuned to 440 vibrations per second. Western music names pitches with seven letters, A to G, repeating in octaves, where each octave doubles the frequency. Between the letters sit sharps and flats, giving twelve equally spaced semitones per octave, which you can see as the white and black keys of a piano. Notes are written on a five-line staff, with a clef such as the treble or bass clef telling you which line is which pitch. Learn to find any note on a keyboard and you hold the map for everything that follows." }, { "id": "song101", "title": "Songwriting and Lyrics", "host": "music", "desc": "Write songs that land: hooks, verse and chorus structure, rhyme, imagery and melody. Practise in Solid Sound at /ss.", "lessons": ["What makes a song", "Song forms: verse, chorus, bridge", "Hooks and titles", "Rhyme, rhythm and imagery", "Writing melody to words", "Finishing and revising"], "intro": "A song marries words and music so that each makes the other stronger. Most popular songs are built from sections: verses tell the story and change their words each time, the chorus carries the main idea and the hook and repeats, and a bridge offers contrast before the final chorus. The hook is the short, memorable phrase or melody listeners carry away, often the title itself. Strong lyrics favour concrete images over abstractions; 'your jacket on my chair' says more than 'I miss you'. In this course you will collect ideas, pick one clear emotion per song, and draft lyrics you can try out right away in Solid Sound at /ss." }, { "id": "prod101", "title": "Music Production Basics", "host": "music", "desc": "From idea to track: the digital audio workstation, recording, beats, arrangement and mixing.", "lessons": ["The DAW and the signal chain", "Recording voice and instruments", "Beats and drum programming", "Arrangement", "Mixing: levels, EQ and space"], "intro": "Most music today is produced in a digital audio workstation, or DAW, software that records, arranges, edits and mixes sound on a timeline of tracks. Sound enters through a signal chain: a microphone or instrument, an audio interface that converts the analogue signal into digital samples, and the DAW itself. Digital audio is described by its sample rate, how many measurements per second (44,100 is the CD standard), and its bit depth, how precise each measurement is. The cardinal rule of recording is gain staging: set input levels high enough to stay clear of noise but low enough never to clip, because distortion from clipping cannot be removed later." }, { "id": "art101", "title": "Visual Art and Design Fundamentals", "host": "vip", "desc": "The elements and principles of design: line, shape, colour, composition and how images guide the eye.", "lessons": ["Elements of art", "Colour theory", "Composition and balance", "Drawing from observation", "Art history in ten works"], "intro": "Artists and designers work with a shared toolkit called the elements of art: line, shape, form, value (lightness and darkness), colour, texture and space. These are the raw materials; the principles of design, such as contrast, balance, emphasis, rhythm and unity, describe how to arrange them. Contrast is often the fastest way to guide the eye: the brightest, sharpest or most saturated spot in an image usually becomes its focal point. Look at the red, black and gold of Solid City and you will see these rules at work, with a dark base, a strong red accent and gold for emphasis. Throughout this c