Sails of Silver now sported the same line-up that had brought it to the height of its success, "Sails of Silver" has often been seen as embodying a different spirit from their classic albums of the 1970s. Prior to "Sails of Silver", the band had always performed songs written by other people, predominantly traditional songs, but also a few 20th century pieces, such as the two Brecht songs on "Storm Force Ten". But on this album they included several songs they had written themselves, including "Let Her Go Down" and "Senior Service". This was the beginning of a trend that continues down to
Forces on sails sail and the apparent wind ("α" ) exceeds the point of maximum lift on the "C"–"C" polar diagram, separation of flow occurs. The separation becomes more pronounced until at "α" = 90° lift becomes small and drag predominates. In addition to the sails used upwind, spinnakers provide area and curvature appropriate for sailing with separated flow on downwind points of sail. Again, in these diagrams the direction of travel changes with respect to the apparent wind (V), which is constant for the sake of illustration, but would in reality vary with point of sail for a constant true wind. In