GuitarChords.netWish You Were Here began on a 12-string
David Gilmour had bought a Martin D12-28 12-string from a friend in 1974. In the first half of 1975, Pink Floyd was at work on a new album at Abbey Road Studios in London. Gilmour sat in the control room of Studio 3 and started to strum that guitar.
A riff came out. In an interview with the musicologist Paul Rappaport, later quoted by Christie's, Gilmour said he began mildly obsessing with the line as it grew. Roger Waters heard it. His ears pricked up, Gilmour recalled, and he asked where that idea had come from.
Gilmour had a habit of playing bits of other people's songs by accident. Waters had learned to check first. This time the line was Gilmour's own. It became Wish You Were Here, the title track of the 1975 album.
The finished cut opens like a tiny car radio. On his 2019 podcast, Gilmour said they ran a microphone out to his car in the Abbey Road car park, turned the dial between stations, and used a bit of that on the song. He played the thin intro on the D12-28, then overdubbed a fuller acoustic solo on his Martin D-35 so it sounds like someone at home joining the broadcast. Gilmour later told Christie's he wished that take had been a little better, and that it was not meant to be slick.
On the record, the thin radio guitar and the fuller D-35 sit side by side. One feels far away. The other feels close, as if a second player has walked into the room.
A Discogs sleeve for the U.S. Columbia LP Wish You Were Here lists Abbey Road Studios from January to July 1975. The same release page dates that Columbia issue to September 12, 1975.
Acoustic Guitar magazine places the original riff in standard tuning with no capo, in the key of G. The magazine says Gilmour built that opening around G major, E minor 7 (Em7), and A7sus4, a hold that keeps the same bright top notes and sits close to A suspended 4 (Asus4). The sung parts stay in open G shapes and move through C major, D major, A minor (Am), and G again. G is the quiet home under the whole song.
You do not need a 12-string or a radio trick to start. Put open G shapes under your fingers and walk the Em7 loop until it feels steady.
If you want the grip that song keeps landing on, start with G major. Both shapes are on that page.