Unbowed by the fearsome sun, the band played while armoured vehicles drove past King Juan Carlos and Queen Sofia, the Prime Minister, Jose Maria Aznar, his ministers and military top brass. The Queen fanned herself furiously as gorgeously arrayed troops marched by.
But behind the glinting medals and silken sashes lies the sombre reality that conscript soldiers are marching off the parade ground at a rate that, if unchecked, could leave Spain without an army.
The government plans to abolish military conscription, the hated mili, within six years. But it may reach the target sooner than it wanted. Spiralling numbers of young conscripts are declaring themselves insumisos - conscientious objectors - and simply leaving.
The new government announced in mid-April that it planned to professionalise the armed forces completely by 2002. The number of insumisos that had stood at 6,000 a month from January to April rose to 8,200 after the announcement and to 9,000 in May.
A pledge to reduce the length of military service from the present nine months to six during the current parliament will increase the need for even more recruits, but is hardly likely to deter legions of youngsters from going awol before they are called up.
Seeking to stave off further defections in the ranks, the Defence Minister, Eduardo Serra, has announced a package of economic proposals designed to tempt new recruits and to avert the prospect of Spain's generals being left without soldiers to command.
In his first parliamentary speech as minister, Mr Serra confessed to worries that the transition to a professional force might charge out of control and be brought to its knees by an avalanche of conscientious objectors.
Measures under consideration include increasing the conscript wage to 30,000 pesetas (pounds 150) per month, waiving income tax for families while their sons are serving, and giving preferential access to public sector jobs to those who had done their duty.
Spain has been debating for years about whether to have a mixed professional- plus-conscript army or a purely professional body. Public opinion favoured the professionals, but the previous Socialist government opted for a mixture because it was cheaper.
Conscientious objection has long been a source of tension in Spain, particularly in the nationalist Basque Country and Catalonia. Until recently an insumiso who refused to undertake community service in lieu could face imprisonment.