As a "native speaker mum" I have often been asked to host English lessons during project weeks at our children's primary school in the German state of Hesse.
The week's topics typically included colours or numbers, so I taught them "I Can Sing a Rainbow" and - you've guessed it - "Head, Shoulders, Knees and Toes".
Flatteringly, all available places on my courses filled up quickly - chiefly, I suspect, because children were keen to perform songs in English when their parents visited at the end of the week.
Foreign parents were fascinated, while German parents were as proud as punch that their children were "singing in English" - which was no mean feat as the majority of the kids did not even speak High German at home.
Yet such innocent fun may now be under threat. A new study in Germany has launched a scathing attack on early foreign-language teaching policies, introduced throughout most German states at the turn of the millennium.
The idea had been to give primary pupils a playful introduction to a foreign language - mostly English - using rhymes, songs and visuals, easing the transition to secondary where English is an important subject. Most states introduced it in grade 3 (age 9); some started in reception.
Yet the results, according to Professor Heiner Boettger of Eichstatt University in Bavaria, have not lived up to expectations. His research shows more than 95 per cent of teachers in Gymnasien (grammar schools) and Realschulen (secondary moderns) are unimpressed by what pupils have learnt and reckon they all reach the same level by the end of grade 5 (age 11), the first year of secondary. Part of the problem was the states' over-eager approach which often failed to provide a proper structure.
Since each of Germany's 16 states is responsible for its own policy, there was also a wide variation in training methods for primary teachers of English. Heinz-Peter Meidinger, chairman of DphV, the German grammar schoolteachers' association, says: "In the city state of Hamburg, primary teachers get further training in English in the form of a four-week crash course, while English teachers at German grammar schools study for a minimum of five years before they take a class."
Both Mr Meidinger and Professor Boettger also criticise the fact that primary school English is taught for only one or two periods a week and that there is no link to what comes afterwards when pupils enter secondary school.
"We have 16 federal states," Professor Boettger says, "and 16 different concepts."
What's needed, according to Mr Meidinger, are clearly defined targets for teaching English at primary schools, as well as academically trained teachers and a minimum of four to five periods a week.
Professor Boettger even suggests crossover application with music, maths and sport being taught in English, too.
As to music, I can vouch for pupil enthusiasm from my guest appearances as a teacher.
Anyone for a song?